Contents - sldrce.tongji.edu.cn · 2019 National Conference on Wind-induced Vibration, Monitoring and Control in Shantou on Mar.22-24th,2019.ProfZHULedongwasinvited to give a keynote

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Contents

Academic Exchange Activities

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Research and Development

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International Publications

(Abstract)

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List of Other Recent

Publications (SCI, EI indexed)

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Academic Exchange Activities1. Prof. YAN Zhiguo gave a presentation on intelligent

disaster prevention and operation and maintenancetechnology of extra-long road tunnel in the ninth annualconference of the maintenance and management branchof China highway society at Chongqing on Jan. 10-11th,2019.

2. Prof. CAO Shuyang, Dr. CAO Jinxin and their studentsattended International Workshop on Wind Effects onBuildings and Urban Environment held in TokyoPolytechnic University, Atsugi, Kanagawa, Japan onMar. 10-12th, 2019. Prof. CAO Shuyang presented anoral paper entitled “Tornado-induced wind loads onstructures” and Dr. CAO Jinxin’s presentation is “Windloads on ground-mounted solar arrays exposed totornado-like vortices”.

3. Prof. CAO Shuyang, Dr. CAO Jinxin and their studentsvisited Large-scale Low Noise Wind Tunnel of RailwayTechnical Research Institute (RTRI) at Maibara, Japanand Railway Technical Research Institute (RTRI) atTokyo, Japan on Mar. 13-14th, 2019.

Volume 16, Number 1, Sept. 2019

Disaster Reduction News Volume 15, Number 2, Jun., 2019

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4. Prof. CAO Shuyang visited Disaster PreventionResearch Institute of Kyoto University to attendGlobal Alliance of Disaster Research Institutes(GADRI), held in Kyoto, Japan on Mar. 14th, 2019.At this meeting, he was elected as the Vice-President (Term: 2019.3-) of International Group ofWind-related Disaster Risk Reduction (IG-WRDRR).

5. Prof. ZHU Ledong and Dr. ZHU Qing attended the2019 National Conference on Wind-inducedVibration, Monitoring and Control in Shantou onMar. 22-24th, 2019. Prof ZHU Ledong was invitedto give a keynote speech on “Theoretical andExperimental Study on Nonlinear Flutter ofLong-span Bridges with bluff-body decks”. Dr.ZHU Qing gave a presentation on “Effects ofVibration and Turbulence on the Wind-inducedTorsional Instability of Bridge Decks”.

6. Prof. SUN Limin attended the Symposium IABSE2019 in Guimaraes, Portugal on Mar.25-31st, 2019.

7. Prof. ZHU Ledong attended the 14th China-Japan-Korea International Workshop on WindEngineering as a workshop organizer in Hangzhouon Mar. 29-31st, 2019.

8. Prof. CAO Shuyang and Dr. CAO Jinxin attendedthe 5th Workshop of the NSFC Key international(regional) cooperative research project entitled“Effects of tornado and downburst on network-likedistributed infrastructures and the risk propagationmechanism”in Beijing Jiaotong University, Beijing,China on Apr. 12-13th, 2019.

9. Prof. ZHU Ledong and Dr. ZHU Qing attended the19th National Conference on Structural WindEngineering in Xiamen on Apr. 18-21st, 2019.Prof. ZHU Ledong gave a presentation titled “Self-limiting and Bifurcation Phenomena of Gallopingon a Rectangular Cross Section and TheirMechanisms”. Dr. ZHU Qing gave a presentationon “Modelling Vortex-induced Distributed Forceon Centrally-slotted Decks via POD”.

10. Prof. SUN Zhi attended the 3rd Ganjiang Forum onCivil Engineering in Jiangxi on Apr. 19-21st,2019and delivered a speech titled “Some Important

Oscillation Patterns for Bridges under MovingVehicles: Process Monitoring & EmergencyCharacteristics".

11. Prof.s LU Xilin, LU Zheng and TONG Leweiattended 7th Structural Engineers World Congresson Architecture and Structure held at Istanbul,Turkey on Apr. 22-28th, 2019. Prof. LU Xilin gavea keynote presentation entitled “New Technologiesfor Seismic Response Control of Tall Buildings”.Prof. LU Zheng gave a parallel presentation entitled“Comparative Studies on Two Additional MassDampers”.

12. Prof. YAN Zhiguo attended the 45th ITA-AITESGeneral Assembly and World Tunnel Congress inNaples, Italy on May 3-9th, 2019. Dr. ZHANGTong gave a presentation on Experimental study on“a novel fire-protection cement-based compositematerial for tunnel linings”. Prof. YUAN Yong andhis team attended this congress too. They gave oralpresentations on design of shaking table tests onatrium-style subway station models under seismicexcitations.

13. Dr. YUAN Xianxun, associate professor at RyersonUniversity in Canada, was invited to visit Collegeof Civil Engineering and the International JointResearch Center for Engineering Reliability andRandom Mechanics (JCERSM) in TongjiUniversity on May 16th, 2019. He delivered alecture titled “Structural Progressive CollapseAnalysis: Concept Establishment and Performance


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Evaluation”. A workshop on the ongoing studies inboth groups and potential cooperation wassuccessfully organized. Prof. CHEN Jianbingchaired the seminar and workshop.

14. Prof. Hector Jensen from the University of SantaMaria in Chile, who is presently a high-end foreignexpert from the State Administration of ForeignExperts Affairs of China and invited by Prof.CHEN Jianbing, delivered a lecture titled"Performance-Based Design Optimization: AStochastic Optimization Approach" at TongjiUniversity on May 17th, 2019.

15. Prof. SUN Limin attended the 6th Forum onSustainable Urban Development on both sides ofTaiwan Strait in Shanghai, China on May 17-18th,2019, and made a keynote speech on “StructuralHybrid Monitoring- Theoretical Framework,Terminology and Experimental Verification”.

16. Prof.s GE Yaojun, CAO Shuyang and ZHAO Linwere invited to attend the Third InternationalWorkshop on Advanced Wind Engineering TestingTechnology (AWETT), which was held inUniversity of Buffalo, USA on May 19-22nd, 2019.

17. Prof. CHEN Jianbing and Ph.D. student, Mr.YANG Jiashu, attended the 13th World Congress ofStructural and Multidisciplinary Optimization

(WCSMO) held in Beijing, China on May 19-24th,2019. WCSMO is the most important congress inthe field of structural optimization, and has beenheld every two years since 1995. Mr. YANG Jiashugave an oral presentation titled “StructuralOptimization Considering Dynamic ReliabilityConstraints via Probability Density EvolutionMethod”, which was well attended.

18. Prof. SUN Zhi, with his students, Mr. FEI Hao andWANG Yucheng attended Moss 2019 in Changsha,Hunan on May 24-26th, 2019. They presented apaper titled “Vibration Cancellation to MovingLoad Problems: How It will Make ForcedResonance Disappear for Single-Span Bridges”.

19. Prof.s LI Jie, CHEN Jianbing, LIU Wei andPENG Yongbo participated the 13th InternationalConference on Applications of Statistics andProbability in Civil Engineering (ICASP13) held inSeoul National University, South Korea on May26-30th, 2019. ICASP is one of the most importantinternational conferences in the area of structuralsafety, reliability and risk analysis organized by theInternational Civil Engineering Risk and ReliabilityAssociation (CERRA). Prof. LI Jie, as the memberof the Board of Directors of CERRA, attended theCERRA Board meetings. Prof. CHEN Jianbing waselected into the Board of Directors of CERRA.

20. Prof.s LU Xilin, JIANG Huanjun, ZHAO Bin andDr. LI Xin took part in the fib Symposium 2019“Concrete-Innovations in Materials, Design andStructures”, held in Kraków, Poland on May27-29th, 2019. Four research papers, “Modellingand Parametric Study of Steel Fiber ReinforcedHigh Strength Concrete Composite Shear Walls”,“Deformation Limit Analysis of Steel ReinforcedConcrete Coupling Beams”, “Research on Seismic


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Behaviour of Full Precast Concrete WallsAssembled by New Horizontal Joints” and“ Contrastive Analysis on Seismic Performancebetween Cast-In-Situ and Precast RC FrameStructure”, were presented during the conference.Prof. ZHAO Bin also chaired the Session 29 “B.2:Prefabrication” on May 29th, 2019. On behalf ofthe fib Shanghai Symposium 2020, Prof. ZHAOBin introduced the preparing work of the comingsymposium and welcomed all the participants tojoin the Shanghai Symposium during the fib TCmeeting and the Closing Ceremony of fibSymposium 2019.

21. Prof. Givoanni Crosta and Dr. Paolo Frattini fromUniversity of Milano-Biccoca, Italy visited TongjiUniversity from May 28th to Jun. 16th. Theyconducted a collaborative research with Prof. LIUFang on the hazard assessment of landslideassociated with methane hydrate production and thesimulation of rockfall trajectory. A seminar aboutthe landslide hazard assessment and prevention washeld and they gave a talk on “Shallow landslidesmapping, monitoring, modeling”.

22. Prof. Ton Vrouwenvelder from TNO, Netherlands,was invited by Prof.s LI Jie and CHEN Jianbing,visited the College of Civil Engineering of TongjiUniversity and the International Joint ResearchCenter for Engineering Reliability and StochasticMechanics (JCERSM) on May 31st, 2019. He wasinvited to give a Wenyuan Forum lecture titled"Dealing with Uncertainty in Structural Analysis"in Room A804, Civil Engineering Building. Prof.Vrouwenvelder is the former President of theInternational Joint Committee on Structural Safety(JCSS), and was bestowed the C.A.Cornell Awardin 2011.

23. The workshop on sustainability of the BuiltEnvironment was co-organized by the InternationalJoint Committee on Structural Safety (JCSS) andthe International Joint Research Center forEngineering Reliability and Stochastic Mechanics(JCERSM). The main purpose of this workshop isto explore how the researches in structural andsystem reliability, stochastic mechanics and riskdecision support can contribute to the sustainabilityof the built environment and the current challengesand possible solutions. More than 20 professors andresearchers were invited and attended thisworkshop on Jun. 1st, 2019, including ProfessorMichael Faber from Aalborg University (Presidentof JCSS), Professor Ton Vrouwenvelder from TNO,the Netherlands and Delft University of Technology(former President of JCSS), Prof. LI Jie fromTongji University (President of the InternationalAssociation for Structural Safety and Reliability(IASSAR)), Prof. ZHAO Yangang from KanagawaUniversity, etc.

24. Prof. LI Guoqiang was invited to attend theRegency Steel Asia symposium2019 conferenceheld in Singapore on Jun. 12th, 2019, and gave aninvited lecture titled “Connecting High-strengthSteel for Construction”.


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25. Prof. LI Guoqiang was invited to attend 6thInternational Conference on Applications ofStructural Fire Engineering(ASFE’19), and gave akeynote lecture titled “Main issues on behavior ofintumescent coatings”.

26. Prof.s ZHU Hehua and YAN Zhiguo gave apresentation on “Intelligent tunnel evacuation andrescue technology based on fiber Bragg grating” inWorld Transport Convention (WTC2019), BeijingChina, on Jun. 13-16th, 2019.

27. Prof. YUAN Yong and his team attended the 7thInternational Conference on Earthquake Geo-technical Engineering held in Roma, Italy on Jun.17-20th, 2019, and gave oral presentations onseismic ground motion amplification pattern ofsoil-structure interactionsystem and shaking tabletest on the asynchronousresponses of the shaft-tunnel junction undertransverse excitations.

Research and Development

1. Dr. CAO Jinxin and Prof. CAO Shuyang initiallycarried out rigid-model wind pressure and forcemeasurements on a high-speed train located on aviaduct in a tornado vortex simulator (Fig.1), toclarify tornado-induced aerodynamic loadingcharacteristics. Two main parameters, swirl ratioand horizontal distance from tornado center to train,were considered. Wind pressure coefficients acrossthe train model are negative regardless of theposition of the pressure taps. The most unfavorablelocation of tornado center for the total aerodynamicloading coefficients of three cars were determinedthrough integration of pressure values across the carsurface. Surface pressure distributions and sectionalforce coefficients along the train axis wereinvestigated to interpret the total aerodynamicloading effects. The experimental findings will behelpful for predicting tornado-induced risks forhigh-speed railway systems.

Fig.1 Test setup

2. Prof. TONG Lewei and his research students areinvestigating seismic behavior of outer ring jointsbetween concrete filled rectangular tubular columnsand H-shaped beams. Low cycle loading tests werecarried out to explore the hysteretic behavior of thiskind of beam-to-column joints with different sizesof outer ring and loading conditions. The testsfound two types of failure modes, namely the localbuckling and fracture mode located at theconnection of beam flange and outer ring, andfracture mode located at the joint panel zone ofcolumn web, respectively. The performances aboutskeleton curve, ductility coefficient, energydissipation capacity and failure mechanism were


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investigated. A finite element model was developedand used for parametric analysis on the effects ofaxial ratio, concrete strength, wall thickness oftubular column and size of outer ring plate onhysteretic behavior of joints. Reasonablesuggestions were put forward for seismic design.

Fig.2 Test setup

(a) CS-P1 (b) CS-P2

(c) CW-P2 (d) MS-P3

(e) MW-P3

Fig.3 Experimental specimen of H-beam to concrete-filledrectangular tubular column

3. Prof. GU Ming and his research team have recentlycompleted the wind pressure test and thecomputation of the wind-induced response ofLeshan Aolin stadium Project. The roof is a large-span spatial structure with a plane dimension of250m×230m. Based on the rigid pressure modeltests in TJ-2 wind tunnel, the wind loads acting onthe main structure and components and claddingwere acquired. Meanwhile, the snow loads on theroof are also evaluated.

Fig.4 Model of Leshan Aolin stadium in wind tunnel

4. Prof. GU Ming and his research team have recentlycompleted the wind pressure test of Tall building ofTilanqiao of Shanghai, a super-tall building withthe height of 180 meters. Based on the rigidpressure model tests in TJ-3 wind tunnel, the windloads acting on the main structure and componentsand cladding were acquired.

Fig.5 Model of tall building of Tilanqiao of Shanghai inwind tunnel

5. Prof. GU Ming and his research team have recentlycompleted the wind pressure test and thecomputation of the wind-induced response of AnqinConvention and Exhibition Center Project. The roofis a large-span spatial structure with a planedimension of 230m×400m. Based on the rigidpressure model tests in TJ-2 wind tunnel, the windloads acting on the main structure and componentsand cladding were acquired. Meanwhile, the snowloads on the roof are also evaluated.


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Fig.6 Model of Anqin convention and exhibition center inwind tunnel

6. Prof. JIANG Mingjing and his team analyticallyinvestigated the wellbore stability for drilling inmarine methane hydrate-bearing sediments byemploying a properly simplified multi-fieldtheoretical model. The new solutions were derivedanalytically for the temperature, seepage pressureand stress/displacement field, considering thechanges in the mechanical and physical propertiesof reservoirs induced by MH dissociation, as wellas the partial coupling of multi-fields. A parametricstudy was finally performed.

Fig.7 Equivalent stresses at the wall of the borehole and thethickness of the dissociated region versus drilling fluidpressure for various drilling fluid temperatures:(a) thickness of the dissociated region and(b) equivalent stresses

7. Prof. JIANG Mingjing and his team proposed ananalytical solution of displacement and stress forexcavation of quasi-rectangular tunnels at shallowdepths. The Schwarz alternating method combinedwith complex variable theory were employed toderive the elastic solution, and convergent andhighly accurate solutions were obtained bysuperposing the solutions in the alternatingiterations. A parametric study was performed toinvestigate the influences of the rectangular/quasi-rectangular tunnel shape, burial depth andsupporting pressure on the ground stresses anddisplacements.

Fig.8 Normalized stresses and displacements along the tunnelboundary versus θ for rectangular/quasi-rectangulartunnels

8. Prof. JIANG Mingjing and his team conducted thenumerical investigation on the microstructure andits evolution under cyclic loading using distinctelement method (DEM). A series of cyclic triaxialtests in drained conditions were numerically carriedout on the DEM specimens with two differentinitial relative densities.

Fig.9 Effect of cyclic amplitude on the cyclic behavior of densespecimen (Dense group 2, qav= 160 kPa):evolutions of(a) deviatoric strain; (b) volumetric strain

9. Dr. LIU Fang’s research group is assessing theefficiency and safety of gas production from asloping hydrate reservoir constrained withconditions in Dongsha area of South China Sea.The effect of a lensing layer above the hydratereservoir is studied. As shown in Fig. 10, thepresence of the lensing layer reduces the productionefficiency in terms of the production rate andenergy utilization, and meanwhile increases thepossibility of landslide triggered by hydrateproduction.

Fig.10 Gas hydrate production efficiency and sloping reservoirstability of production cases with various strategies


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10. Prof. ZHOU Ying’s research team completed themechanism and numerical investigation of a novelLow-Prestressed Self-Centering Energy DissipationBrace (Fig.11(a)). The brace is designed to achievefull self-centering characteristics within thecomponent level with near-zero requirements ofprestressing. The assemblage of the brace’s innermember, intermediate member and post-tensioned(PT) tendon system forms a unique self-centeringmechanism. An outer member that consists of aratchet system and a yielding element in seriesworks as a tension only energy dissipative device(Fig.11(b)), which effectively reduces the demandfor prestressing. Numerical investigation resultsshow that the brace generates a flag-shapehysteretic characteristic (Fig.11(c)) while onlyrequiring a small amount of PT tendon area,prestressed force and prestressed ratio (Fig.11(d)).The results also show that the brace effectivelyreduces structural residual displacement and controlthe maximum displacement comparable to abuckling-restrained brace.

(a) (b)

(c) (d)

Fig.11 Low-prestressed self-centering energy dissipation brace

11. Dr. LIU Fang’s research group is studying the upliftbearing capacity of a plate anchor near a productionwell of hydrates. A code is developed in Python tocommunicate TOUGH+HYDRATE and ABAQUS.The thermo-hydro-mechanical-chemical (THMC)one-way sequential coupled analysis is achievedand adopted to simulate the uplift response of theplate anchor during gas production from a hydratereservoir configured according to the drilling data

of South China Sea. The Evolution of spatialdistribution of pore pressure and the spatiotemporaldistribution of hydrate saturation during gasproduction are shown in Fig. 12. The results showthat the uplift bearing capacity of the plate anchor ismainly affected by two mechanisms: 1) the processof depressurization, which improves the bearingcapacity of the plate anchor by increasing frictionalstrength of the surrounding soils; 2) the dissociationof hydrate, which leads to a decrease in cohesion ofthe surrounding soils and therefore reduces thebearing capacity of the plate anchor. When theanchor plate is close to the well, these twomechanisms dominate by turns, and the upliftbearing capacity of the anchor first increases andthen decreases. After production ends and the porepressure in the reservoir recovers to the hydrostaticconditions, the bearing capacity of the plate anchordecreases by about 20% of the original value beforeproduction (Fig. 13).

(a)

(b)

Fig.12 (a) Evolution of spatial distribution of pore pressure and(b) spatiotemporal distribution of hydrate saturationduring gas production


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Fig.13 The evolving ultimate uplift capacity of the anchor underdifferent well-anchor distances

12. Prof. JIANG Huanjun’s research team proposed anew type of self-centering beam-column joint withcurved steel plate, which has higher energydissipation capacity and can provide certain lateralstiffness under large earthquakes. A series oftheoretical analysis, finite element simulation andexperimental research were carried out on this newjoint. Through theoretical analysis, calculationformula of the bearing capacity of the new joint inthe elastic and plastic phase was obtained.Parameter analysis on the new joint was conductedby using finite element analysis software ABAQUS.The low-cycle cyclic loading test was carried out onseven specimens with different parameters. Theresponses of three steel frame structure, one pureframe, one frame with steel slit shear walls and oneframe with both steel silt shear walls and the newjoints, were compared under different levels ofearthquakes.

13. The research object of Zhang Jingzhou(Prof. LIGuoqiang’s research team) mainly focuses on thecollapse resistance of steel frames with concreteslabs under six column-removal scenarios (generalmiddle, general side, corner, penultimate-side,middle-edge-intermediate and interior-edge-cornercolumns). The influence of vierendeel effect on thecollapse resistance of multi-storey steel structuresunder side and corner column loss scenarios is alsostudied.

14. Prof. ZHOU Ying’s research team proposes a noveltracking algorithm for structural health monitoring.Visual object tracking is a fundamental part incomputer vision. Recently, Siamese based trackers

have achieved balanced accuracy and speed.However, most of these trackers do not fully exploitthe similarity metrics in Siamese network. Thus,multi decoders are designed: one branch forforeground and background classification, anotherfor bounding box regression, and the third maskbranch for segmentation. Recently, the researchteam has proposed the Siamese single decodernetwork (SiamSDN) (Fig.14(a)). To boost thetracking speed and accuracy, multi subtasks oftracking are integrated into one decoder.Specifically, the template and the search branchextract deep features of the exemplar and instance.Then, it is presented a novel elementwisecorrelation operator, and the decoder interpret themaximum response and similarity into a singlefull-scale score map. The position and scale ofbounding box are formulated through statisticalparameter estimation. Benefit from the integrateddesign, the tracker operates at 67 fps whileachieving competitive performance against thestate-of-art trackers in multiple benchmarks(Fig.14(b)).

(a)

(b)

Fig.14 The structure of SiamSDN and tracking results onbenchmarks

15. Prof. LI Guoqiang’s research team has conducted astatic test on the collapse resistance of a large-scalesteel frame with flat concrete slabs subjected to anedge-column loss was launched (shown in Fig.15).The purpose of the test is to investigate theresistance-vertical displacement relationship at thecolumn-removal location and the final failure mode


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of the substructure. It was found that even withoutexternal horizontal restraints, tensile catenary andmembrane actions can significantly develop at largedeflections for an edge-column loss scenario. Thecatenary action in the double-span beam was morenotable than that in the beam perpendicular to it. Asshown in Fig.15(d), positive yield lines diagonallydistributed on the slab while negative yield lineselliptically distributed along the edges of the slab.Dynamic effects of steel framed-structures underedge-column removal scenario are investigated byconducting comparative experiments on twoidentical steel frames with concrete slabs. Oneframe suffers from a static edge-column loss, whilethe other is subjected to a corresponding dynamiccolumn loss which is simulated by imposing animpact on a three-hinged column. The verticaldeflections at the column-removal location of thetwo frames are reported and compared. It wasfound that due to the dynamic effects, the dynamicdeflection was about 61% greater than the staticdeflection (6.5mm) for the same gravity load(148kN).

(a) (b)

(c) (d)

Fig.15 Static test setup and final deformation mode

16. Prof. LI Guoqiang’s research team in collaborationwith China State Construction Technical Centre(CCTC), completed comparative experimentalstudy on seismic performance of large scale RCframes with Energy-Dissipative Rocking Columnsystem at Structural Engineering Laboratory ofCCTC in Beijing. The Energy-Dissipative Rocking

Column (EDRC) is a combination of rockingcomponents and metal energy-dissipativecomponents. It consists of two steel columnbranches with pinned supports which are connectedby distributed steel strip dampers. The teststructures were two-story two-bay reinforcedconcrete frames with and without EDRC,respectively, as shown in Fig. 16(a, b). Twopseudo-dynamic tests with different levels ofseismic intensities and one quasi-static test wereconducted. In general, the damage degree of RCframe with EDRC is much lower than that of thebare RC frame. After the tests, the base and joint ofEDRC were free from severe damage, while largenumber of cracks were observed at column baseand beam-to-column joint of bare RC frame, asshown in Fig. 16(c-f).

(a) (b)

(c) (d)

(e) (f)

Fig.16 Comparison of RC frames with and without EDRC

17. Prof. CHEN Suwen and her PhD Student Miss LUYujia have carried out a series of monotonicloading and cyclic loading-unloading tests on SGPinterlayer at room temperature and various strainrates (1×10-3s-1 to 1×10-1s-1) (Fig.17a). The forcewas recorded via a load cell (Fig.17b). The strainwas measured using DIC testing system consistingof two CCD cameras interfaced with a computer(Fig.17c). The specimens were unloaded at


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different preset stresses and deformations beforeand after yielding respectively, and then reloaded(Fig.18). Obvious residual deformations were foundafter tests (Fig.19). The true stress-strain curveswere extracted (Fig.20) and characteristicmechanical parameters were identified.

(a) (b)

(c)Fig.17 Photo and schematic of testing setup

Fig.18 Unloading scheme

Fig.19 Photos of specimens after tests

Fig.20 True stress-strain curves at 0.1s-1

18. Prof. CHEN Suwen and her PhD student Miss WEIXinna conducted experiments concerning coupledeffects of temperature and strain rate on mechanicalproperties of high strength structural steel Q690. A300 kN MTS high temperature electronic materialtesting machine used for quasi-static tests (Fig. 21a).Dynamic tensile tests of Q690D were conductedwith the improved SHTB system (Fig. 21b). Atvarious strain rates and temperatures, truestress-strain curves were obtained, as shown infig.22 and fig.23. Characteristic mechanicalparameters were then identified.

(a) MTS (b) STHBFig.21 Test equipment

Fig.22 True stress-strain curve at room temperature

Fig.23 True stress-strain curve at different strain rate andtemperature

19. Prof. CHEN Suwen and her research teamdeveloped a steel structure safety monitoringsystem based on the component temperature tounderstand the real-time safety status of thestructure under fire. The safety monitoring test on


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steel truss structure under fire was carried out toverify the feasibility of the monitoring system andstudy the response and collapse performance ofsteel truss subjected to fires. The results showedthat the test conformed to the three stages of thegeneral indoor fire development process. Thecomponent temperature reached about 900 °C. Theresidual mid-span displacement after fire is 480 mm,which indicates the structure has collapsed. Thecomparison between the output of the monitoringsystem and the experimental phenomena withrecorded data showed that the monitoring systemcould accurately reflect the damage of thecomponent. The collapse of tested steel truss infires can be predicted form the overall stability anddisplacement response of the structure in advanceby the monitoring system. It will support the firerescue and avoid casualties caused by unpredictablefailure of structures in fire.

Fig.24 Fully-developed fire

Fig.25 Tested truss after fires

Fig.26 Gas temperatures during fire

Fig.27 Displacements of truss during fire

20. Prof. SUN Feifei’s research team conducted twogroups of high-strength steel (HSS) end-plateconnection tests consisting of a flush and anextended end-plate connection specimen. Testresults revealed that the pinching effect of the flushend-plate connection was more severe than that ofthe extended end-plate connection when thethicknesses of the end plates were the same. Thehysteretic behavior of the HSS end-plate connectionwas investigated through the experimental,theoretical and numerical methods (Fig. 28). Basedon the comparison, the traditional multilinear modelwas modified considering the bolt bendingdeformation and the beam flange rotation (Fig. 29)resulted by the prying forces. Furthermore, avalidation was performed to prove that the modifiedmultilinear model can be used to predict theconnection behavior of the HSS end-plateconnection under cyclic loading.

Fig.28 Comparison between results of the numerical sumulationand the experiment


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Fig.29 (a) Mode 1: connection deformation without consideringthe beam flange rotation;(b) Mode 1: connection deformation considering thebeam flange rotation.

21. Prof. SUN Feifei’s research team proposed a novelnegative stiffness amplifying damper (NSAD) byintroducing a negative stiffness (NS) spring to theflexibly-supported-viscous-damper systems (Fig.30). The proposed NSAD not only achievessignificant damping magnification effect, but alsopreserves the property of negative stiffness. Thisfeature is attractive for reducing both displacementand structural acceleration when subjected toearthquakes. The closed-form expressions ofoptimal parameters for an undamped SDOF systemwith NSAD was also derived by modifying the‘fixed point’ method of tuned mass dampers. Then,the performance of NSAD is investigated andevaluated under stochastic excitations, pulseexcitations, and real earthquakes (Fig. 31). Resultshows that the optimal NSAD can substantiallyreduce displacement and acceleration responsessimultaneously.

Fig.30 Physical realization of NSAD

Fig.31 Acceleration response spectra under different types ofpulses

22. Prof. TONG Xiaohua’s research team haveprogress in the research of underwater high-speedcamera network. In order to obtain the spatialposition, instantaneous velocity, instantaneousacceleration and other motion states of the keytargets of measured structure in the waterenvironment, a distributed high-speed video-grammetry system for underwater engineeringexperiments has been developed. Four maincontents of this underwater photogrammetry systemare listed as follows: (1) A high-speed cameranetwork measurement scheme is proposed to realizesynchronous, dynamic and efficient acquisition ofmeasurement target motion sequences underwatermulti-view environment and large field of view ;(2) Establishing an improved underwater photo-grammetric model to achieve millimeter locationaccuracy of the target points based on themulti-media optical imaging equations;(3) Establish a refractive comprehensive frameworkconsidering multi-layer camera calibration toachieve sub-pixel reprojection error of the targetpoints in underwater high-speed camera array;(4) In order to realize the fast computation ofthree-dimensional dynamic parameters, Adistributed parallel processing scheme is proposed.Moreover, the proposed measurement scheme isapplied and verified in underwater shaking tabletest, the positioning accuracy of the target pointscan achieve around 0.5 mm, can meet the accuracyrequirement of this experiment.


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(a) (b)

Fig.32 3D reconstruction of underwater target points

(a) (b)

(c) (d)

Fig.33 (a) EXX strain field; (b) EYY strain field;(c) U displacement field; (d) V displacement field

23. Prof. CHEN Zhiyi’s research team established theflexibility ratio formula for the underground shaftsand conducted three-dimensional time historyanalyses for the shafts with different flexible ratio.The results show that the internal forces distributionpattern and deformation modes of the shafts aredetermined by the depth-to-width ratio and themagnitude of the internal forces are affected by theinner-to-outer diameter ratio with the same shaft'sdepth-to-width ratio and surrounding soilconditions.

Fig.34 Deformation mode of underground structure and soils:(a) shear distortion of the free-field soil medium;(b) shear distortion of the corresponding soil and(c) flexural distortion of the vertical shaft

24. Prof. CHEN Zhiyi’s research team proposed a fastseismic analysis method for shafts based on the

theory of embedded beam in Winkle foundation.They deduced the control equation of shaft underearthquake excitations in frequency domain and thecorresponding analytical solutions of shaftresponses. The dynamic responses were translatedbetween time domain and frequency domain byFast Fourier Transform (FFT) and inverse FastFourier Transform (iFFT). Compared with the 3Ddynamic time history analysis method, resultsshowed that the fast seismic analysis method cannot only ensure calculation accuracy, but alsocalculation efficiency.

Fig.35 Schematic of a shaft under earthquakes excitation

25. Prof. CHEN Zhiyi’s research team introduced theself-centering energy-dissipation column base forthe underground subway station and verified theeffectiveness of self-centering energy-dissipationcolumn base through three-dimensional timehistory analyses. The analysis results show that theself-centering energy-dissipation column baseeffectively decreases the internal forces of centralcolumn and the peak and residual values of storydrift and column drift are also minimized about4%–5%.

Fig.36 Underground structure with SCED column base:(a) total view of whole structure, (b) top view, and(c) side view of SCED column base (unit: mm)


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26. Prof. YU Haitao derive an analytical solution forthe longitudinal bending stiffness of a segmentalliner, typically used on tunnels built with a shield.A parametric analysis, using the new analyticalsolution, is also included to investigate theinfluence of key parameters such as the thickness ofthe rubber gaskets, the ratio of the liner thickness tothe internal tunnel diameter, and the transversebending stiffness of the tunnel cross section on thelongitudinal bending stiffness of the tunnel.

Fig.37 Longitudinal model for the liner of shield tunnels:(a) assembly of rings or elements; (b) cross section of thetunnel; (c) element composition: segments, bolts andrubber gaskets; (d) detail view of the same elementcomposition in Fig. 37c

27. Prof. ZHU Hehua’s research team propose a novelbio-inspired cement-based composite materialsystem that can improve the fire resistance ofengineering structures. This bio-inspiredcementitious system, which functions in a mannersimilar to that of sweat glands and skin in thehuman body, consists of APP-PER-EN composite,synthetic reinforcing fibers, and concrete binder.The APP-PER-EN composite is mainly composedof ammonium polyphosphate (APP), pentaerythritol(PER), and melamine (EN), with low-densitypolyethylene (LDPE) as the base material, which isprepared by melt compounding in a twin-screwextruder followed by grain cutting moldingtechnique. The novel composite system is expectedto exhibit a promising prospect in the fire resistanceof engineering structures.

28. Prof. ZHU Ledong’s research team conducted windtunnel tests on the sectional model of Xin Jin HeBridge. The aerodynamic performance of the bridgeagainst both flutter and vortex-induced vibrationwas investigated.

(a) (b)

Fig.38 Wind tunnel tests on sectional model of Xin Jin HeBridge

29. Prof. ZHU Ledong’s research team conducted windtunnel tests on the aeroelastic model of the FourthBridge over the Panama Canal at the Pacific Side.The prototype project is a cable-stayed bridge witha total length of 1088m and a main span of510m.The tests carried out in the TJ-2 wind tunnelinvestigated the galloping, buffeting andvortex-induced vibration performance of itsfree-standing tower.

Fig.39 Aeroelastic model of the bridge tower erected in the TJ-2wind tunnel

30. Various diagnosis methods were used to identifythe damage of wind turbine blades. Among thevarious damages of wind turbine blades, someonemakes the statistical performance characteristics ofthe time-series representations of wind turbineshifted. A. Prof. TANG Hesheng and the research

Fig.40 Laboratory test wind turbine structureLaboratory testwind turbine structure


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team presented an experimental verification of thestatistical time-series methods, which utilizeadapted frequency response ratio (FRR),autoregressive (AR) model parameter and ARmodel residual as performance characteristics, fordiagnosing the damage of wind turbine blades.Specifically, the statistical decision-makingtechniques are used to identify the status patternsfrom turbine vibration data.

Fig.41 Test statistic Z(w) fordamage detection

Fig.42 Test statistic X for damagedetection

31. The small first passage probability of nonlinearstructures under nonstationary seismic excitationimplies a prohibitive computational demandbecause of the epistemic uncertainties rooted instructure system. Assoc. Prof. TANG Hesheng andthe research team proposed a hybrid Kriging-highdimensional model representation (Kriging-HDMR)methodology for drastically simplifying this task.The epistemic uncertainties with the well-definedbounds but no concrete distribution form are welladdressed by interval model. The first passageprobability of the generic response process, inwhich the epistemic uncertainties involved, isrepresented by the conditional univariate extremevalue distribution (EVD) of structural parameterswith interval form. Then, a Kriging assisted HDMRtogether with third moment saddle pointapproximation (TMSA) is proposed to alleviate thecomputational burden of two loops Monte-Carlosimulations and provides an accurate depiction ofpossible model outcome. The differential evolution(DE) interval optimization strategy is performed toaccelerate the post process of searching the lowerbound (LB) and upper bound (UB) of first passageprobability with interval form. To investigate theinfluence of epistemic uncertainties rooted instructural parameters, a sensitivity analysis forinterval model is presented.

Fig.43 Flowchart of dynamic reliability analysis of structuresystem with epistemic uncertainties

32. Prof. SUN Zhi’s research team conductedexperimental investigations and numericalsimulations on frequency comb sequencing ofrunning load induced equi-span continuous beambridge oscillation. Series of running ballexperiments were carried out in Tongji University(see Fig. 44). Bridge modal oscillation patterns (seeFig.45) were sequenced through bridge accelerationresponse measurements. The sequencing showsthree groups of frequency-multiplication harmonicsfor beam modal oscillations and forcedsynchronization junctions along the ridge lines. Thetests will benefit the area of precise behaviorcontrol, as well as disaster risk alarming for thiscategory of dynamic systems.

(a) (b)

Fig.44 Running ball tests of a 2-span continuous beam

Fig.45 Frequency comb sequencing results


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International Publications (Abstract)

1. Fragility analysis of the roof structure of low-rise buildings subjected to tornado vortices(Published in Journal of Wind Engineering and Industrial Aerodynamics, 2019, 189: 45-55)

Fragility analysis of the roof structure of low-rise buildings subjected to tornado vorticesWANG Jin, PANG Weichiang, CAO Shuyang*, ZHOU Qiang and LIAO Haili

ABSTRACT: The fragility curves of roof failures for wood-frame low-rise building were developed in thisstudy with the focus on the roof sheathing panels and roof-to-wall connections. Two different nail spacingsfor roof sheathing panels and three types of roof-to-wall connections were considered. This study focused onthe first failure of roof sheathing panels without considering the sequential loss of the sheathing panels, andthe unit failure of effective wind zones containing different numbers of roof-to-wall connections. The tornadosimulator-based dataset was used for determination of the statistics of wind loads, without considering thetranslational motion effects of tornado vortices. The results show that the failure probability of roof isdependent on the proximity of a tornado to a building and the opening azimuth on walls. Additionally, thecombined effects of pressure drop and aerodynamic interactions dominate the failure modes of roof system.The obtained fragility curves in this study can be used to estimate the maximum tangential wind speed of thetornado vortices and the local oncoming tangential wind speed at roof height. The estimation of tornadointensity using the present results is likely to approach the lower-bound of wind speed estimation in WSEC(2006) report.

2. Seismic performance of high-strength-steel frame equipped with sacrificial beams ofnon-compact sections in energy dissipation bays(Published in Thin-Walled Structures, 2019, 139: 169-185)

Seismic performance of high-strength-steel frame equipped with sacrificial beams ofnon-compact sections in energy dissipation bays

CHEN Yiyi and KE Ke

ABSTRACT: This work focuses on the seismic performance of high-strength-steel frame equipped withmild-carbon-steel sacrificial beams of non-compact sections in energy dissipation bays, namely theHSSF-NCEDB structure. This work was commenced with a test program of a HSSF-NCEDB system as afeasibility study. The test results indicate that the novel structure exhibits the desirable damage-controlbehavior with inelastic actions locked in the sacrificial beams with non-compact sections for the expecteddeformation range. Even though both high strength-steel members and sacrificial beams with non-compactsections were restricted by the limited energy dissipation, ductile manner was observed. A finite element (FE)model was established, and good agreement between the test results and the FE results was obtained. Forpractical applications, the concept of the buckling hinge was developed for quantifying the stable energydissipation stage of sacrificial beams with non-compact sections. Lastly, the effectiveness of theHSSF-NCEDB system for mitigating the post-earthquake residual deformations was demonstrated bypreliminary nonlinear dynamic analyses of single-degree-of-freedom oscillators with validated hystereticmodels. The research findings from this work indicate that the HSSF-NCEDB structure is a promising optionfor structures in low-to-moderate seismic regions.


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3. Experiment and constitutive modeling on cyclic plasticity behavior of LYP100 under large strainrange(Published in Construction and Building Materials, 2019, 202: 507-521)

Experiment and constitutive modeling on cyclic plasticity behavior of LYP100under large strain range

HE Qun, CHEN Yiyi, KE Ke, Michael C.H. Yam, WANGWei

ABSTRACT: Low yield point (LYP) steel is a promising material for energy dissipation device resistingseismic actions, and is expected to experience large strain when subjected to strong earthquakes. In order tooffer a better understanding of the cyclic behavior of LYP steel under large strain range, cyclic tests of eight(8) coupons made of LYP100 under the strain amplitude ranging from _10% to +12% are performed. Evidentworkhardening, early re-yielding, and strain range dependence are characterized in the cyclic loading tests.To illustrate these characteristics, the peak stress of every cyclic loop and the elastic region of the unloadingprocess are examined. Based on the analysis results of the peak stress and the elastic region, a modifiedYoshida-Uemori model is proposed to quantify the cyclic behavior of LYP100, and the correspondingnumerical algorithm is developed. In addition, a practical method based on the derivative-free optimizationtheory is proposed to calibrate the material parameters of the novel model. The proposed constitutive modelshows a satisfactory accuracy for describing the cyclic behavior of LYP100 under large strain range.

4. Physical simulations on wind loading characteristics of streamlined bridge decks undertornado-like vortices(Published in Journal of Wind Engineering and Industrial Aerodynamics, 2019, 189: 56-70)

Physical simulations on wind loading characteristics of streamlined bridge decks undertornado-like vortices

CAO Jinxin*, RE Shaolan, CAO Shuyang and GE Yaojun

ABSTRACT: Tornado risks for highly important long-span bridges in tornado-prone regions can not beneglected. Rigid-model wind pressure measurements on a streamlined bridge deck were conducted using atornado vortex simulator, to clarify tornado-induced surface pressure distributions, aerodynamic loadcoefficients and total force coefficients. We focused on two main parameters: swirl ratio and horizontaldistance from tornado center to deck. Obvious discrepancies were observed between tornado-induced windloading and results from conventional boundary-layer wind tunnels. Strip theory was not applicable sincepressure distributions vary for different sections of the deck along the bridge axis. The absolute values ofmean pressure coefficients for the deck section near tornado center are largest among all tested sections alongthe bridge axis. The most unfavorable mean sectional drag force coefficients were found when the bridgemodel is located at the tornado core radius and largest mean sectional lift force coefficients at the tornadocenter. With increase in swirl ratio, magnitudes of mean pressure coefficients as well as mean and fluctuatingsectional aerodynamic load coefficients become smaller. The unfavorable locations for fluctuating rollingmoment coefficients are different from those for mean values, which indicates that the quasi-steadyassumption becomes invalid for tornado-induced rolling moment coefficients. Total force coefficients overthe entire deck were investigated to evaluate the non-uniform loading characteristics. The findings will behelpful for predicting tornado-induced responses and risks for highly important long-span bridges.


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5. Experimental Verification of The Statistical Time-Series Methods for Diagnosing WindTurbine Damage(Published in International Journal of Structural Stability and Dynamics. 2019.19(1). DOI:10.1142/S021945541940008X)

Experimental Verification of The Statistical Time-Series Methods forDiagnosing Wind Turbine Damage

TANG Hesheng, LING Suqi, WAN Chunfeng and XUE Songtao

ABSTRACT: This paper presents an experimental verification of the statistical time-series methods, whichutilize adapted frequency response ratio (FRR), autoregressive (AR) model parameter and AR model residualas performance characteristics, for diagnosing the damage of wind turbine blades. Specifically, the statisticaldecision-making techniques are used to identify the status patterns from turbine vibration data. Forexperiments, a small-size, laboratory-used operating wind turbine structure is used. The performance of eachmethod in diagnosing damages simulated by saw cut in three critical positions in the blade are assessed andcompared. The experimental results show that these methods yielded a promising damage diagnosiscapability in the condition monitoring of wind turbine.

6. Analytical investigation of wellbore stability during drilling in marine methane hydrate-bearingsediments (Published in Journal of Natural Gas Science and Engineering, 2019, 68: 1-17)

Analytical investigation of wellbore stability during drilling inmarine methane hydrate-bearing sediments

WANG, Huaning, CHEN Xupeng, JIANG Mingjing* and GUO Zhenyu

ABSTRACT: Methane hydrates (MHs) have attracted increasing interest as potential alternative cleanenergy resources. However, drilling and MH exploitation in marine methane hydrate-bearing sediments(MHBS) face new challenges associated with MH dissociation and complex multi-physics coupling. Thisstudy mainly focuses on wellbore stability during drilling in marine MHBS by employing a properlysimplified multi-field theoretical model. The new solutions are derived analytically for the temperature,seepage pressure and stress/displacement field, considering the changes in the mechanical and physicalproperties of reservoirs induced by MH dissociation, as well as the partial coupling of multi-fields.Theaxisymmetric plane strain wellbore model is simplified, where the infinite ground is divided into threeannular regions with different physical/mechanical properties. The closed-form solutions for temperature andseepage pressure fields are addressed by assuming steady-state heat transfer and fluid flow, by which we findthat the temperature and pressure distribution, as well as the size of dissociated region are closely related tothe relative thermal conductivity and permeability of the regions. An additional infinite region is introducedto obtain the decayed solutions of displacement. The analytical solutions agree very well with the resultsfrom finite element method (FEM) in that the conditions models are completely consistent, and the analyticalresults qualitatively agree with experimental data and the results from numerical simulation under complexconditions other methods. A parametric study is finally performed to investigate the influence of the relativethermal conductivity and permeability of the dissociated region on the size of the dissociated region, as wellas the influence of the drilling fluid temperature/pressure and the reduction in the elastic modulus/cohesion ofthe dissociated region on wellbore stability.


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7. Formulae for Hot-spot Stress Concentration Factors of Concrete-Filled CHS T-joints Based onExperiments and FE Analysis (Published in Thin-walled Structures. Vol.136, 2019, Pages 113-128)

Formulae for Hot-spot Stress Concentration Factors of Concrete-Filled CHS T-jointsBased on Experiments and FE Analysis

TONG Lewei*, CHEN Kepeng, XU Guowen, ZHAO Xiaoling

ABSTRACT: Fatigue of welded concrete-filled tubular joints is a new subject to be investigated, comparedwith fatigue of welded tubular joints without concrete which has been studied well. Fatigue cracking isusually located at the hot spot stress of a welded concrete-filled tubular joint. A method of calculating its hotspot stress is essential for fatigue strength assessment. Hot spot stress concentration factors (SCF) of weldedconcrete-filled circular hollow section (called as CFCHS) T-joints respectively under axial force and in-planebending are investigated experimentally and numerically in this paper. SCF testing was carried out on tenCFCHS T-joints with different non-dimensional geometric parameters β (ratio of brace to chord diameter), 2γ(ratio of chord diameter to thickness) and τ (ratio of brace to chord thickness). The experimental findingsshows in most cases, a remarkable decrease in SCFs of CFCHS T-joints, compared with circular hollowsection T-joints without concrete. Finite element (FE) modelling with 3D quadratic hexahedral solid elementwas developed and verified by the experimental data. It is found that the conversion relationship SCF = 1.2SNCF (strain concentration factor) can be adopted for CFCHS T-joints. Using the reliable FE modelling,parametric study was conducted to know the effect of non-dimensional parameters on SCFs of CFCHST-joints. Based on multiple regression analysis, a series of formulae are recommended for calculating SCFs inthe chord and brace of CFCHS T-joints subjected to the axial force and in-plane bending in the brace and inthe chord respectively, which are validated by both the experimental data and FE modelling.

8. Local and post-local buckling of normal/high strength steel sections with concrete infill(Published in Thin-Walled Structures, 2019, 138: 155-169)

Local and post-local buckling of normal/high strength steel sections with concrete infillSONG Yuchen, LI Jie, CHEN Yiyi

ABSTRACT: Steel sections in steel-concrete composite columns have been proofed to be less susceptible tolocal buckling and have higher capacity than bare steel columns, attributed to the internal restraints providedby the infilled concrete. This article presents a theoretical study concerning the local and post-local bucklingof fabricated normal and high strength steel sections filled with concrete, including concrete filled steeltubular (CFST) sections and partially encased composite (PEC) sections. A nonlinear finite element (FE)model was established and validated to simulate the behavior of steel plates in contact with concrete, withboth geometric imperfections and residual stresses explicitly incorporated. This model was subsequentlyapplied in a parametric study to investigate the effects of several critical factors on the local bucklingbehavior of box and I steel sections. Based on the available test and FE results, new design formulas wereproposed to predict the local buckling and post buckling ultimate strengths of concrete-restrained steel boxand I sections, taking into consideration high material strengths, residual stresses and geometricimperfections. The enhancement of strength due to the presence of concrete infill was confirmed through acomparison with the post-buckling strength of bare steel sections. Recommendations were also made fordesign purpose based on the formulas proposed.


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9. Special Issue: Resilience and Sustainability of Civil Infrastructures under Extreme Loads(Published in Sustainability, 2019, 11(12): 3292)

Special Issue: Resilience and Sustainability of Civil Infrastructures under Extreme LoadsLU Zheng*, ZHOU Ying, YANG Tony and PAPALOU Angeliki

ABSTRACT: The special issue entitled Resilience and Sustainability of Civil Infrastructures underExtreme Loads'' updates the state of the art and perspectives focused on cutting-edge approaches to enhancestructures' resilience and sustainability under extreme loading events, including theoretical investigation,numerical simulation, and experimental study, keeping an eye on the seismic performance of civilstructures. Notably, some innovative energy dissipative devices and resilient structural forms, which areencompassed in this special issue, would provide valuable references for the engineering application ofresilient and sustainable civil infrastructures in the near future.

10. Experimental Study on a New Damper Using Combinations of Viscoelastic Material andLow-Yield-Point Steel Plates(Published in Frontiers in Materials, 2019, 6: 100)

Experimental Study on a New Damper Using Combinations of Viscoelastic Material andLow-Yield-Point Steel Plates

JIANG Huanjun, LI Shurong and HE Liusheng*

ABSTRACT: To enhance the seismic resilience of coupled reinforced concrete shear walls, a new damperworking in the replaceable coupling beam is proposed in present study. The new damper is a combination ofmetallic damper and viscoelastic (VE) damper. The metallic damper consists of an I-shaped steel beam withmultiple low-yield-point steel plate webs paralleled to each other; the VE damper is composed of multiplelayers of VE material bonded between multiple steel plates. Through the composite use of viscoelasticmaterial and low-yield-point steel, the new damper is expected to work effectively against both theearthquake and the wind. To study the respective mechanical behavior of each component of the combinednew damper, eight metallic dampers, two VE dampers, and one combined damper are tested under cyclicloading first. The variable parameters of the metallic damper are strength grade of web steel, webdimensions, and end stiffener configuration. It is found that the effect of the strength grade of web steel ismost significant. Compared with the metallic damper using the steel web with normal strength grade, theductility, ultimate plastic shear rotation, and cumulative plastic shear rotation of the damper using thelow-yield-point steel web are much larger. The effect of web dimensions on the deformation capacity isslight. With the addition of end stiffener, plasticity concentrates thereby, which prevents the flange-to-endplate weld fracture. The VE damper exhibits extraordinary deformability. The storage modulus, shear lossmodulus and loss factor of the VE material decrease with the increase of strain amplitude. The storagemodulus and shear loss modulus of the VE material decrease slightly as the excitation frequency increaseswithin the range between 0.1 and 1 Hz, and the effect of the excitation on the loss factor is not significant.At last, the combined damper, an assembly of one metallic damper component and two VE dampercomponents, is tested, which exhibits stable hysteretic behavior and excellent deformability. The predictedyield shear strength and elastic stiffness agree well with test results.


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11. Study on seismic reliability of UHVDC transmission systems(Published in Shock and Vibration, 2019)

Study on seismic reliability of UHVDC transmission systemsYAO Kun and QIAN Jiang*

ABSTRACT: Electric power system is critical to maintain the welfare of the general public with impact oneconomic losses and other cascading. In this paper, the seismic reliability of the ultra-high-voltage directcurrent (UHVDC) transmission system was evaluated from a perspective of the subsystem fault logic. Anassessment model of system seismic reliability was proposed based on the state enumeration method. A casestudy was presented by taking a typical 800 kV UHVDC transmission system as the example. The finiteelement models of major components in the UHVDC transmission system were established to evaluate theirseismic reliability. The results reveal that though the seismic reliability of major components seemssatisfactory overall, the UHVDC transmission system may still suffer from seismic hazards to a certaindegree due to the complexity of the full system. This calls for a further enhancement in seismic designrequirements of the electrical equipment.

12. Experimental investigation on cyclic behavior of Q690D high strength steel H-sectionbeam-columns about strong axis(Published in International Engineering Structures, 2019, 189: 157-173)

Experimental investigation on cyclic behavior of Q690D high strength steel H-sectionbeam-columns about strong axis

HAI Letian, LI Guoqiang, WANG Yanbo*, SUN Feifei and JIN Huajian

ABSTRACT: Q690 high strength steel (HSS) is a structural steel with yield-to-tensile ratio being generallygreater than 0.90 and elongation lower than 20%, resulting in considerable decrease in steel memberductility. In seismic affecting zones, steel members are usually designed as compact sections to avoidpremature local buckling for attaining fully developed plasticity. However, this approach increases thepotential risk of fracture for Q690 steel structures. Thus, cyclic behaviors of Q690D HSS compact sectionbeam-columns need to be thoroughly investigated. To this end, this paper conducted five cyclic loading testsof Q690 HSS compact H-section beam-columns based on a reliable testing system. The influences of theflange width-to-thickness ratio, web height-to-thickness ratio, axial-load ratio and overall slenderness on thefailure mode, energy dissipation capacity and hysteretic behavior were analyzed. It shows that plastic localbuckling dominates the failure mechanism of all the specimens without overall buckling being observed.The ultimate inter-story drift ratio was more than 1/50. The Q690 welded beam-columns with Class 1 andClass 2 H-section exhibit not only favorable plastic deformability but also excellent energy dissipationcapacity and therefore could be applied in seismic steel frames. To attain accurate evaluation of damage andcyclic response, two damage models and two point-oriented hysteretic models were selected and combinedto form four damage-based hysteretic models. The four hysteretic models were then implemented tosimulate the cyclic loading experiments. It was found that the ultimate strength-oriented hysteretic modelincorporated with Kumar Satish damage model provides the most accurate simulation. The hysteretic modelparameters were calibrated using experiments data. The simulation results of the developed hysteretic modelmatch well with those experimental curves.


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13. Aluminum alloy channels subjected to web crippling(Published in Advances in Structural Engineering, Vol.22, No.7, 2019, pp1617-1630)

Aluminum alloy channels subjected to web cripplingZHOU Feng* and Young Ben

ABSTRACT:When This article reports experimental and numerical investigations of aluminium alloy plainand lipped channels subjected to web crippling. A total of 240 data are presented that include 24 test resultsand 216 numerical results. A series of tests was conducted first on channels fabricated by extrusion using6063-T5 and 6061-T6 heat-treated aluminium alloys under end-two-flange and interior-two-flange loadingconditions. The concentrate transverse loads were applied by means of bearing plates. The flanges of thespecimens were not fastened (unrestrained) to the bearing plates. A non-linear finite element model is thendeveloped and verified against experimental results. Geometric and material non-linearities were included inthe finite element model. It was shown that the finite element model closely predicted the web cripplingstrengths and failure modes of the tested specimens. Hence, the model was used for an extensive parametricstudy of cross-section geometries, and the web slenderness value ranged from 24.0 to 207.3. The test resultsand the web crippling strengths predicted from the finite element analysis were compared with the designstrengths obtained using the American, Australian/New Zealand and European specifications for aluminiumstructures. An empirical unified web crippling equation with new coefficients for aluminium alloy channelsunder end-two-flange and interior-two-flange loading conditions is proposed. Since two failure modes of webbuckling and web yielding were observed in the tests, the web crippling strength is also predicted using theproposed theoretical design rules for channels. The web crippling strength is the lesser of the web bucklingstrength and web yield strength.

14. Cell Renormalized Fokker-Planck equation method (CR-FPK) for fractional order nonlinearsystem(Published in International Journal of Non-Linear Mechanics, 2019, 110, 94-103)

Cell Renormalized Fokker-Planck equation method (CR-FPK)for fractional order nonlinear system

JIANG Zhongming and LI Jie

ABSTRACT: In this paper, the random response of nonlinear dynamic systems with fractional order term areexamined. In this context, an efficient approach called CR-FPK method is proposed to numerically obtaintransient stochastic response for those nonlinear systems under white-noise excitation in which damping is offractional order. This approach is based on the extension of stochastic averaging method and the process ofcell renormalization. By first revisit the process of equivalent linearization and stochastic averaging, theMarkov property of envelope response is firstly settled. Then the idea of cell renormalization is introduced toreconstruct the derivative moments and the corresponding Fokker-Planck-Kolmogorov (FPK) equation of theenvelope process. The transient and stationary probability density function (PDF) of the envelope process isfinally obtained by solving the transient FPK equation. The reliability of this method is verified by using thebenchmark results of analytical method and Monte Carlo Simulation. The conclusion and the issues to befurther studied are presented in the last part.


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15. Spectrum analysis-based model for the optimal outrigger location of high-rise buildings(Published in Journal of Earthquake Engineering, 2019)

Spectrum analysis-based model for the optimal outrigger location of high-rise buildingsZHOU Ying*, XING Lili and ZHOU Guangxin

ABSTRACT: The outrigger system is a current alternative to reduce the dynamic response of high-risebuildings. The aim of the study is to develop analytical methods for earthquake response of a conventionaloutrigger system and to determine the optimal outrigger location. First, a theoretical simplified model isdeveloped based on a dynamic time-history load and is further improved by mode-superposition responsespectrum method. The model is then calibrated via an ANSYS model, and the simplified model is applied toperform parametric analyses to acquire the optimal outrigger location of each scheme. Subsequently, all dataobtained from parametric analyses are summarized to solve the fitting equation of optimal outrigger location.Finally, a comparison of the results between time-history and spectra analysis suggests that the spectrumanalysis-based simplified model effectively simulates the seismic behavior of structure with an outrigger andits corresponding fitting equation reasonably expresses the optimal outrigger location of the aforementionedtype of structure under seismic action.

16. Experimental Study of Sliding Hydromagnetic Isolators for Seismic Protection(Published in Journal of Structural Engineering, 2019, 145(5).)

Experimental Study of Sliding Hydromagnetic Isolators for Seismic ProtectionPENG Yongbo, DING Luchuan and CHEN Jianbing, et al.

ABSTRACT: Sliding isolation, as one of the modalities of base isolation, has demonstrated its value inseismic hazard mitigation. Conventional sliding isolation systems, however, may exhibit unacceptable largesliding displacements under severe earthquakes and may suffer a risk of unpredictable impact effect due tothe insufficient isolation gap. A novel base isolation system that uses sliding hydromagnetic bearings hasbeen proposed recently to overcome these shortcomings. These bearings comprise steel tubes with apressurized internal fluid and attached permanent magnets, and slide over aluminum base plates also withattached permanent magnets. They minimize the friction between bearings and base plates, generate adamping force that reduces the bearings displacements to practical levels, and introduce a restoring force anda displacement constraint. In the present study, a sliding hydromagnetic isolator is designed, fabricated, andtested experimentally to assess its performance as a seismic protection system. Additionally, numericalsimulations are carried out for quantifying the repulsive, damping, and friction forces involved. It is foundfrom these studies that the applied loads on the hydromagnetic bearing does not produce fluid leakages,O-ring damage, or scratch marks on the base plates; the bearing's friction coefficient does not exhibit aconventional friction-vertical load correlation and is therefore lower and more stable than in existing slidingisolators due to the effect of oil-solid interface; and the pressurized fluid significantly reduces the frictionalforce between bearing and base plate and facilitate thus the bearing's sliding; the repulsive force increasesdramatically with the bearing displacement and may effectively prevent bearings from sliding off their baseplates.


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17. Steady-state dynamic response of a gradient elastic half-plane to a load moving on its surfacewith constant speed(Published in Archive of Applied Mechanics, 2019)

Steady-state dynamic response of a gradient elastic half-plane to a loadmoving on its surface with constant speed

PEGIOS I. P., BESKOU S. Papargyri*, ZHOU Ying and HE Pengfei

ABSTRACT: The problem of determining the steady-state dynamic response of a granular elastic half-planeto a load moving on its surface is solved analytically. The granular material is modeled as a gradient elasticsolid with one material constant with length dimensions in addition to the two classical elastic moduli. Theload is uniformly distributed of constant magnitude and moves with constant speed. The resulting two partialdifferential equations of motion are of the sixth order with respect to the horizontal x and vertical ycoordinates and of the second order with respect to time t. These equations are solved with the aid ofcomplex Fourier series involving x and t, which reduce them to a system of two ordinary differentialequations, which can be easily solved. The so-obtained solution is used to easily assess the microstructuraleffect on the various response quantities through parametric studies.

18. Performance evaluation of base-isolated structures with sliding hydromagnetic bearings(Published in Structural Control & Health Monitoring , 2019, 26(1).)

Performance evaluation of base-isolated structures with sliding hydromagnetic bearingsPENG Yongbo, DING Luchuan and CHEN Jianbing

ABSTRACT: Being an efficient technique for mitigating the seismic response of structures, base isolation iswidely used in earthquake engineering practice. The sliding hydromagnetic bearing is viewed as a promisingisolation system for seismic protection, owing to its adaptive damping energy dissipation, mild deformationconstraint, and easy assembly and maintenance. To verify the applicability and efficiency of slidinghydromagnetic bearings, a performance evaluation of base-isolated structures with a sliding hydromagneticbase-isolation system is carried out in this paper. Numerical simulations are performed to explore thedynamic behaviors of sliding hydromagnetic bearings fabricated recently, for which two models, the powerfunction and polynomial models, are proposed. Parameter identification and model validation are carried outusing the data from numerical simulations and quasi-static tests. Backward differential formulas areemployed to solve the stiff differential equation invoked by the Coulomb friction associated with the models,which bypasses the computational challenges inherent in conventional integral schemes. For a real-timedefinition of the instantaneous frequency in the models, the Hilbert-Huang transform is utilized. Comparativestudies reveal that the sliding hydromagnetic bearing has an advantage over the lead rubber bearing and thecurved surface slider in the control of structural displacement, structural velocity, and structural acceleration.Furthermore, the residual displacement yielded in the sliding hydromagnetic base-isolation system merelyshifts the starting position of the bearing on the next movement, and the sliding surface and deformationconstraints remain approximately as the initial condition.


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19. A study of snow drifting on a flat roof during snowfall based on simulations in a cryogenic windtunnel (Published in Journal of wind engineering and industrial aerodynamics, 2019, 188, 269-279)

A study of snow drifting on a flat roof during snowfall based on simulationsin a cryogenic wind tunnel

QIANG Shengguan, ZHOU Xuanyi, Kenji Kosugi, GU Ming

ABSTRACT: Wind tunnel simulation is a very important approach to studying snow drifting and predictingdrift snow loads on roofs. A complete simulation of the full process of wind-induced snow accumulation on aroof should include snow drifting both during snowfall and after snowfall. However, in most of the previousstudies, snow drifting phenomenon was only simulated without concurrence of snowfall. We herein describesimulations of snow drifting on a flat roof during snowfall, which were carried out in a cryogenic wind tunnelusing artificial snow particles. Based on the results, we demonstrate the differences and similarities betweensnow drifting during snowfall and that without concurrent snowfall. The developments of snow transportbefore saturated state apparently follow the same rule, no matter whether there is concurrent snowfall or not.However, it seems that the required fetch distance for a saturated saltation state can be reduced by snowfall. Aformula is proposed to more reasonably describe the development of snow transport rate. Based on testresults and deductions, some discussions on similarity requirements for modelling snow drifting on roofsduring snowfall will be presented. Finally, a prediction of the prototype fetch distances under different windand snowfall conditions will also be presented, which can provide a guide for further research andengineering application.

20. Combined Bending and Web Crippling of Aluminum SHS Members(Published in Steel and Composite Structures, Vol.31, No.2, 2019, pp173-185)

Combined Bending and Web Crippling of Aluminum SHS MembersZHOU Feng* and Young Ben

ABSTRACT: This paper presents experimental and numerical investigations of aluminum tubular memberssubjected to combined bending and web crippling. A series of tests was performed on square hollow sections(SHS) fabricated by extrusion using 6061-T6 heat-treated aluminum alloy. Different specimen lengths weretested to obtain the interaction relationship between moment and concentrated load. The non-linear finiteelement models were developed and verified against the experimental results obtained in this study and testdata from existing literature for aluminum tubular sections subjected to pure bending, pure web crippling, andcombined bending and web crippling. Geometric and material non-linearities were included in the finiteelement models. The finite element models closely predicted the strengths and failure modes of the testedspecimens. Hence, the models were used for an extensive parametric study of cross-section geometries, andthe web slenderness values ranged from 6.0 to 86.2. The combined bending and web crippling test results andstrengths predicted from the finite element analysis were compared with the design strengths obtained usingthe current American Specification, Australian/New Zealand Standard and European Code for aluminumstructures. The findings suggest that the current specifications are either quite conservative or unconservativefor aluminum square hollow sections subjected to combined bending and web crippling. Hence, a bendingand web crippling interaction equation for aluminum square hollow section specimens is proposed in thispaper.


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21. Analytical study of ground responses induced by the excavation of quasi-rectangular tunnels atshallow depths(Published in International Journal for Numerical and Analytical Methods in Geomechanics, 2019, 43:2200-2223)

Analytical study of ground responses induced by the excavation ofquasi-rectangular tunnels at shallow depths

ZENG Guangshang, WANG Huaning* and JIANG Mingjing

ABSTRACT: The construction of quasi-rectangular tunnels at shallow depths is becoming increasinglycommon in urban areas to efficiently utilize underground space and reduce the need for backfilling. To clarifythe mechanical mechanism of the stresses and displacements around the tunnels, this study proposesanalytical solutions that precisely account for quasi-rectangular tunnel shapes, the ground surface, the tunneldepth and the ground’s elastic/viscoelastic properties. The Schwarz alternating method combined withcomplex variable theory are employed to derive the elastic solution, and convergent and highly accuratesolutions are obtained by superposing the solutions in the alternating iterations. Based on the solution and theextended corresponding principle for the viscoelastic problem, the time-dependent analytical solutions for thedisplacement are obtained for the ground assuming any viscoelastic model. The analytical solutions agreewell with the FEM numerical results for models that are completely consistent, and qualitatively agree withfield data. Furthermore, based on the stress solution combined with the Mohr-Coulomb failure criterion, thepredicted initial plastic zone and propagation directions around the tunnels are qualitatively consistent withthose determined by the limit analysis. A parametric study is performed to investigate the influences of therectangular/quasi-rectangular tunnel shape, burial depth and supporting pressure on the ground stresses anddisplacements.

22. Experimental investigation of concrete-filled single-skin and double-skin steel oval hollowsection stub columns (Published in Thin-Walled Structures, Vol.140, 2019, pp157-167)

Experimental investigation of concrete-filled single-skin anddouble-skin steel oval hollow section stub columns

ZHOU Feng* and Young Ben

ABSTRACT: Both types of single-skin and double-skin of concrete-filled steel tubular columns have beenexperimentally investigated in this study. The skin of the composite columns was constructed using steel ovalhollow section (OHS) tubes. A series of tests was performed to investigate the effects of the geometricdimension of steel OHS and concrete strength on the behaviour and strength of composite columns. Theoverall width-to-thickness ratio of the OHS tube sections ranged from 15.8 to 62.6. The structuralperformance of the composite columns was investigated using different nominal concrete cylinder strengthsof 40, 70 and 100 MPa. The composite column lengths were chosen so that the length-to-width ratiogenerally remained at a constant value of 3 to prevent overall column buckling. The concrete-filled OHS tubespecimens were subjected to uniform axial compression. The test strengths, load-axial shortening relationshipand failure modes of the composite columns were presented in this paper. The test strengths were comparedwith the design strengths calculated using the American Specification and European Code for composite steeland concrete structures. It was shown that the design strengths do not agree well with the experimentalresults.


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23. Distinct element analysis of the microstructure evolution in granular soils under cyclic loading(Published in Granular Matter, 2019, 21(2): 39-)

Distinct element analysis of the microstructure evolution ingranular soils under cyclic loadingJIANG Mingjing*, ZHANG An and LI Tao

ABSTRACT: Granular soils exhibit very complex macroscopic mechanical responses when subjected tocyclic loading. To enhance the understanding of the cyclic behaviors of granular soils and provide significantinsights into the constitutive modelling, this paper investigates the microstructure and its evolution undercyclic loading using distinct element method (DEM). A series of cyclic triaxial tests in drained conditionswere numerically carried out on the DEM specimens with two different initial relative densities. At particlescale, both the coordination number and contact fabric were investigated to study the microstructureevolution of the granular soils. The simulations indicate that the evolutions of coordination number andcontact fabric are highly dependent on the relative density and cyclic mode. A threshold value for the fabricanisotropy exists under cyclic loading, and once the threshold is reached, the internal structure of thespecimen tends to be unstable, and the critical coordination number is reached at the specimen failure. Thecontact normal fabric tensor is always coaxial with the stress tensor under cyclic loading regardless of thesand relative density and cyclic model. Although there is no unique relationship between the contact normalfabric and stress, a uniqueness relationship between strong contact fabric and stress can be observed.

24. Experimental investigations of failure modes of reinforced concrete beams without webreinforcement(Published in Engineering Structures, 2019, 185, 47-57)

Experimental investigations of failure modes of reinforced concrete beamswithout web reinforcement

XU Taozhi and LI Jie

ABSTRACT: This paper reported an experimental investigation into the stochastic nonlinearities inherent inreinforced concrete (RC) beam without web reinforcement. A series of specimen tests were conducted with astatic monotonic four-point bending regime. Three kinds of RC beams (total of 27 specimens) without webreinforcement of three shear span-depth ratios of 5.1, 4.6 and 4.0 were designed. Each kind of beams had 9samples. All beams were constructed in the same condition and at the same time. Specifically, the materials(both concrete and reinforcement bars) used in the beams were derived from the same batch, and the sametesting program was performed during the experiments. Statistical nonlinearity responses to beams with threeshear span-depth ratios, including the strain-deflection curves of longitudinal reinforcement bars, crackpatterns, failure modes, and load-deflection curves were obtained from the tests. Different failure modesoccurred in the beams with the same shear span-depth ratio. The probabilities of different failure modes ofRC beams without shear reinforcement were statistically calculated based on the test results. It is found thatthe randomness of the mechanical properties of the materials results in the stochastic initial damagedistribution and the subsequent stochastic nonlinear evolution of the beams. In addition, the shear span-depthratio is an important parameter, which significantly affects the stochastic failure mode in the investigatedmembers.


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25. Experimental and Analytical Investigation of D-type Self-centering Steel Eccentrically BracedFrames with Replaceable Hysteretic Damping Devices(Published in Journal of Structural Engineering (ASCE), 145(1), 2019, pp1-13)

Experimental and Analytical Investigation of D-type Self-centering Steel Eccentrically BracedFrames with Replaceable Hysteretic Damping Devices

TONG Lewei, ZHANG Yunfeng*, ZHOU Xin, Arshia Keivan and LI Ruipeng

ABSTRACT: This paper presents the results of an experimental investigation of D-type self-centeringeccentrically braced frames (SCEBF) subjected to cyclic loading. Analytical formulation of the SCEBFmodule frame’s load-displacement relationship is first presented. A total of five one-bay one-story SCEBFmodule frame specimens were experimentally tested under cyclic loading to investigate their seismicbehavior. Finite-element simulation study of Specimen SCEBF2 was also conducted to assist with specimendesign. The replaceable hysteretic damping (RHD) devices made of low-yield steel were installed at thecorners of a rocking link beam to use the amplified motion due to the rocking link beam’s rotation and gapopening for energy dissipation. The experimental test results revealed that all the SCEBF specimens werecapable of recentering and that the damage was confined to the RHD devices. It was also found that aftersevere cyclic loading, the SCEBF module frames with replaced RHD devices exhibited almost identicalstiffness, strength, recentering ability, and energy dissipation capacity to those of the original structure.

26. Turbulent Wind Field Simulation of Wind Turbine Structures with Consideration of the effect ofRotating Blades(Published in Advanced Steel Construction, Vol.15, No.1, 2019, pp82-92)

Turbulent Wind Field Simulation of Wind Turbine Structures with Consideration of the effectof Rotating Blades

HUO Tao, TONG Lewei* and Fidelis R. Mashiri

ABSTRACT: In order to achieve the wind-induced vibration response analysis and fatigue analysis, thisstudy conducts the wind field simulations around tubular tower and rotating blades of typical pitch-controlled1.25MW wind turbine structures, respectively. Based on field test data, there is a large difference between theturbulent wind spectrum for the rotating blades and classic wind spectrum adopted by the non-rotating bladesand tubular tower. In this study, first, the auto and cross-rotational Fourier spectrums are deduced based onthe physical mechanism, with particular focus on the influences of the rotational effect and the correlationbetween different points located on the same and different blades. Then, the Davenport type coherencefunction is optimized. The high accuracy of the rotational Fourier spectrum model is verified by comparingwith the real data. Relevant parameter analysis of the rotational Fourier spectrum is conducted. Finally,turbulent wind fields around the tubular tower based on the Kaimal spectrum and the rotating blades based onthe rotational Fourier spectrum are simulated by means of the harmony superposition method. The resultsindicate that the calculated wind spectrums have good agreement with the target wind spectrums. Therefore,the proposed approach in this study is feasible for the turbulent wind field simulation of wind turbinestructures.


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27. CFD simulation of drifting snow loads on gable roofs: impact of roof slope(Published in Journal of wind engineering and industrial aerodynamics, 2019, 185, 16-32)

CFD simulation of drifting snow loads on gable roofs: impact of roof slopeZHOU Xuanyi, ZHANG Yu, KANG Luyang, GU Ming

ABSTRACT: A series of 2D steady RANS CFD simulations are conducted in this study to investigate theimpact of roof slope on the snow redistribution on gable roofs. A small value of turbulent Schmidt number,which is calibrated by trapping efficiency from experiments, is adopted to enhance the snow particles’turbulent diffusion in the CFD simulations for snow phase. And a scaled model test is conducted in the windtunnel to validate the accuracy of numerical simulation, in which the silica sand was used to model snowparticles. To uncover the mechanism of wind effects on the snow redistribution on gable roofs, the simulationresults of wind-flow patterns, wall friction velocity of the roof surface, snow concentration and snowdistributions are analyzed in detail for various roof slopes (5°-60°). Based on the features of wind-flowpatterns and distribution patterns of snow, the gable roofs are classified into two categories: low slope whereflow separates strongly at the leading edge and high slope where flow separates strongly at the roof ridge.The critical roof slope is between 20º and 25º.

28. Modal behavior factors for the performance-based seismic design of R/C wall-frame dualsystems and infilled-MRFs(Published in Soil Dynamics and Earthquake Engineering, 2019)

Modal behavior factors for the performance-based seismic design of R/C wall-frame dualsystems and infilled-MRFs

Muho Edmond V., QIAN Jiang* and Beskos, Dimitri E.

Abstract: Modal behavior (strength reduction) factors qᾸk for the performance-based seismic design of planereinforced concrete wall-frame dual systems and infilled moment resisting frames are proposed. Instead ofusing a single and constant behavior (strength reduction) factor q (R) as all modern seismic design codes do,herein are proposed different such factors for the first few significant modes of the structure. Moreover, theseqᾸk are constructed as functions of period, different deformation targets and soil types and thus, they aresuitable for a performance-based design in a force-based design scheme. A linear analysis in conjunction withan elastic acceleration response spectrum with its ordinates divided by qᾸk provides a design base shear whichis able to produce seismically designed frames which account for both strength and deformationrequirements. In contrast to the code-based seismic design procedure which is accomplished in two steps, i.e.,first for strength and second for deformation satisfaction, the proposed method eliminates the second step dueto its deformational dependent qᾸk. Moreover, these qᾸk can be used to design for up to four performance levelsdepending on the design needs. Explicit expressions for qᾸk are derived from extensive parametrical studiesinvolving non-linear tiime-history analyses of 19 wall-frame dual systems and 19 infilled moment resistingframes under 100 far-fault historical ground motions corresponding to the four soil classes of Eurocode 8, forsix deformation targets and four performance levels. The proposed method is demonstrated and validatedwith realistic design examples, which show its advantages over the force-based design method of Eurocode 8.


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29. Stochastic single footfall trace model for pedestrian walking load(Published in International Journal of Structural Stability and Dynamics, 2019, 19(3), 1950029)

Stochastic single footfall trace model for pedestrian walking loadCHEN Jun, DING Guo and ŽIVANOVIĆ Stana

ABSTRACT: Developing a model for the dynamic force generated by a pedestrian's foot on a supportingstructure (single footfall trace model) is crucial to advanced numerical analysis and vibration serviceabilityassessment of the structure. A reliable model needs to reflect the inter-subject and intra-subject randomnessof human walking. This paper introduces a stochastic single footfall trace model in the form of a Fourierseries in which body weight, walking frequency, and the first eight harmonics are treated as randomvariables. An experiment used 73 test subjects, walking at a range of pacing frequencies, to record force timehistories and the corresponding gait parameters. Two variability descriptors were used to indicateinter-subject and intra-subject randomness. Further statistical analysis identified the relationships betweenkey parameters as well as the probability distribution functions of random variables. In the final step, anapplication of the proposed single footfall trace model was developed and tested. The proposed modelrepresented the experimental data well in both time and frequency domains.

30. Seismic design methodology for self-centering reinforced concrete frames(Published in Soil Dynamics and Earthquake Engineering, 2019, 119: 358-374)

Seismic design methodology for self-centering reinforced concrete framesLU Xilin*, JIANG Chun, YANG Boya and QUAN Liumeng

ABSTRACT: This paper presents a new design approach for self-centering reinforced concrete frames(SRCFs). SRCF is a seismic resilient structure characterized by minimal structural damage and little residualdeformation under seismic excitations. This remarkable seismic performance is achieved by speciallydesigned self-centering beam-column joints and column-base joints. These joints connect beams and columnsby clamping force provided by unbonded post-tensioning steel. By this means, when the lateral load exceedsserviceability level (i.e. gravity load, frequent earthquake and wind load), the gaps at self-centering joints areallowed to open and the columns are allowed to uplift at the base. The opening and uplifting behaviorsignificantly mitigates the damage in "plastic hinge area", where conventional concrete frame intends tosacrifice in exchange for ductility and energy dissipating capacity. After unloading all the gaps betweencomponents will close under clamping force, and the components thus restore their original position withnegligible residual deformation. This state change of opening and close makes the conventional designmethodology no longer applicable for SRCFs. Despite its extraordinary seismic performance, the absence ofapplicable design method hinders the application of SRCFs. In this paper, key configurations of SRCFs aresummarized based on existing research, and load capacities of different limit states are analyzed. A two-phasedesign approach is presented based on these load capacities. In the first phase, the elastic performance of thestructure is designed to accommodate the gravity load and meet the displacement requirement under frequentearthquakes. The detailed design of post-tensioning steel, damping devices and the reinforcement of thecomponents are determined in the second phase to achieve the performance target under strong earthquakes.Design examples are given to illustrate the design approach. Time history analyses of design examples areconducted to verify the validity of this approach. Analysis result indicates that this approach can be used todesign structures to achieve predefined performance targets with reasonable conservative.


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31. Error estimate of point selection in uncertainty quantification of nonlinear structures involvingmultiple nonuniformly distributed parameters(Published in International Journal For Numerical Methods In Engineering, 2019, 118(9), 536-560)

Error estimate of point selection in uncertainty quantification of nonlinear structuresinvolving multiple nonuniformly distributed parameters

CHEN Jianbing and CHAN Jianpeng

ABSTRACT: The error analysis for the selection of representative point sets (RPSs) in multidimensionalrandom-variate space assigned with arbitrary nonuniform distribution with compact support for uncertaintyquantification is developed by extending the Koksma-Hlawka inequalities, which bound the worst error withsome kind of discrepancy of the RPS and the variation of the integrand. The novel concepts of theEF-discrepancy and the GF-discrepancy are introduced, and the connection and equivalence between themare inquired into. Based on such theoretical basis, the error estimate of selecting RPSs in the standardizedspace instead of that in the original physical space is studied, showing that the standardization of the inputrandom variables does not increase, but usually reduce, the error bound by GF-discrepancy. The extendedKoksma-Hlawka inequality also establishes the theoretical basis for the error estimate of the probabilitydensity evolution method. Besides, the closed-form expressions for the EF-discrepancy are given in theAppendix. A numerical example involving a complex nonlinear engineering structure modeled by the finiteelement method is studied, showing the accuracy of the proposed approach.

32. Optimal vertical configuration of combined energy dissipation outrigger(Published in the Structural Design Tall Special Buildings, 2019, 28(4): 1-17)

Optimal vertical configuration of combined energy dissipation outriggerXING Lili, ZHOU Ying* and AGUAGUINAMario

ABSTRACT: The damped outrigger system emerged as an improvement of the conventional outriggers withthe aim to provide supplemental damping and to contribute to the vibration control in super tall buildingswhere this system is usually applied. In addition to viscous dampers (VDs), buckling-restrained braces(BRBs) have also been employed as energy dissipating members in outriggers. Nevertheless, the combineduse of outriggers with VDs and BRBs in the same structure has not yet been studied. Such combination cancontribute to achieve an effective multiperformance design of super tall buildings. This paper presents a studywhose main objective was to determine the optimal vertical combination of two types of energy dissipationoutriggers to control the seismic responses of a 9-zone super tall model structure. Outriggers with VDs(OVDs) and outriggers with BRBs (OBRBs) were placed at the different zones of the structure consideringall the possible combinations and in configurations of up to four outriggers. The effects of these combinationson the seismic performance of the structure were studied through parametric analysis and optimizationmethods. This form of the outrigger system is defined in this paper as combined energy dissipation outriggersystem. The results indicate that when two energy dissipation outriggers are used, the combination of OBRBplus OVD shows superior seismic performance compared with other double-outrigger configurations. Inaddition, the results show that the locations of OVDs and OBRBs play an important role in the structurebehavior; it was found that it is more beneficial to place OBRBs above OVDs.


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33. Comparison study of two criteria for identification of structural dynamic stability(Published in Science China-Technological Sciences, 2019, 62(5), 856-867)

Comparison study of two criteria for identification of structural dynamic stabilityZHOU Hao and LI Jie

ABSTRACT: Dynamic stability analyses of structures are becoming increasing prevalent in applications fortall buildings and space structure designs. This paper presents an effective energy criterion for identifying thedynamic stability of generalized structures through the modification of an earlier developed energy criterionfor hardening structures. Two time-varying effective energy indices are introduced to account for the dynamicstability of both the hardening and deteriorating structures; one for the description of structural properties,i.e., the structural effective intrinsic energy, and the other for the measurement of the input energy, i.e., thevalid external work. It is shown that a structure's stability can survive provided the effective intrinsic energyis always less than the valid external work during a dynamic excitation. The first passage of the effectiveintrinsic energy over the valid external work indicates the dynamic instability of the structure. A comparisonstudy is carried out regarding the validity and applicability between the energy and effective energy criteriaas applied to the dynamic stability analysis of three different structures.

34. Dynamic response and shear demand of reinforced concrete beams subjected to impact loading(Published in International Journal of Structural Stability and Dynamics, 2019, 1950091)

Dynamic response and shear demand of reinforced concrete beamssubjected to impact loadingZHAO Wuchao and QIAN Jiang*

Abstract: Reinforced concrete (RC) beams under the impact loading are typically prone to suffer shearfailure in the local response phase. In order to enhance the understanding of the mechanical behavior of theRC beams, their dynamic response and shear demand are numerically investigated in this paper. A 3Dfinite-element model is developed and validated against the experimental data available in the literature.Taking advantage of the above calibrated numerical model, an intensive parametric study is performed toidentify the effect of different factors including the impact velocity, impact mass and beam span-to-depthratio on the impact response of the RC beams. It is found that, due to the inertial effect, a linear relationshipexists between the maximum reverse support force and the peak impact force, while negative bendingmoments also appear in the shear span. In addition, the local response of the RC beams can be divided into afirst impact stage and a separation stage. A shear plug is likely to be formed near the impact point at the firstimpact stage and a shear failure may be triggered near the support by large support forces. Based on thesimulation results, simplified methods are proposed for predicting the shear demand for the two failuremodes, whereas physical models are also established to illustrate the resistance mechanism of the RC beamsat the peak impact force. By comparing with the results of the parametric study, it is concluded that the sheardemand of the RC beams under the impact loading can be predicted by the proposed empirical formulas withreasonable accuracy.


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35. Fatigue reliability analysis of concrete structures based on physical synthesis method(Published in Probabilistic Enginneering Mechanics, 2019, 56, 14-26)

Fatigue reliability analysis of concrete structures based on physical synthesis methodLI Jie and GAO Ruofan

ABSTRACT: A new method, namely the physical synthesis method, is proposed for fatigue reliabilityanalysis of concrete structures. With the fatigue damage development as a basis of fatigue reliability analysis,the stochastic fatigue damage model for concrete is introduced to obtain the damage evolution process.Afterwards, the theoretical framework of the physical synthesis method is described, and the generalizedequations for the proposed method is presented, through which the structural reliability could be solved in anefficient and physically meaningful way. Subsequently, the physical synthesis method is applied to analyzethe fatigue reliability of concrete structures by developing a fatigue damage-based failure criterion. Further,the implement process of the proposed method is described in detail to fulfill the assessment of the fatiguereliability for concrete structures. Finally, the application of the proposed method is carried out on the fatiguereliability analysis of a concrete bridge in engineering to demonstrate the validity and effectiveness of theproposed method. By analyzing, the probability density function of the structural response of the bridge afterthe probability dissipation is obtained. Meanwhile, the fatigue reliability of the bridge is well evaluated byintegrating the remaining probability density function.

36. Orthogonal experimental investigation of steel-PVA fiber-reinforced concrete and its uniaxialconstitutive model(Published in Construction and Building Materials, 2019, 197: 615-625)

Orthogonal experimental investigation of steel-PVA fiber-reinforced concreteand its uniaxial constitutive model

ZHOU Ying*, XIAO Yi, GU Anqi, ZHONG Guangchun and FENG Siyuan

ABSTRACT: A concrete mixture consisting of steel fibers (S) and polyvinyl alcohol fibers (PVA) has beenproven to be an effective type of hybrid fiber-reinforced concrete (HyFRC). To further investigate theengineering potential of S-PVA HyFRC, this paper studies the effects of different factors on mixtureperformance, and establishes uniaxial constitutive models through an orthogonal experiment. A total offifteen factors were incorporated. Slump test and various mechanical tests were conducted. Then, amethodology to assess the parameter combination considering various performance indicators was proposedand used in this study to maximize concrete performance. Finally, the generalized and the simplifiedcompressive and tensile constitutive prediction models of S-PVA HyFRC were established and the predictedcurves were compared with the test curves. The results show that the interaction factors are not negligible inS-PVA HyFRC. Cast process significantly influences mixture workability and strength, but it has no impacton toughness. Parameter combination assessments among five performance indicator categories wereperformed and the assessment methodology was verified. The generalized constitutive prediction model wasalso verified by the test curves. Nevertheless, the simplified model may cause large errors and should only beused to roughly estimate the mixture property in the preliminary design stage of an engineering project.


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37. Building Information Model-based finite element analysis of high-rise building communitysubjected to extreme earthquakes(Published in Advances In Structural Engineering, 2019, 22(4,SI), 971-981)

Building Information Model-based finite element analysis of high-rise building communitysubjected to extreme earthquakes

REN Xiaodan, FANWeida, LI Jie and CHEN Jun

ABSTRACT: Starting from the Building Information Model, a pre-processing procedure is proposed in thiswork to develop the refined finite element model of buildings and building community. The structuralmembers which are represented by three-dimensional solid entities in Building Information Model areconverted to lines and planes according to their geometric characteristics. To meet the requirements of finiteelement analysis of building structures, the lines are discretized by the beam elements and the surfaces arediscretized by the shell elements. The damage plasticity model is implemented to simulate the damage andfailure of concrete, and the classic plasticity model is chosen for steel. The simulations of high-rise buildingand building community are performed with the help of large computing server. The damage patterns ofdifferent building structures are obtained and discussed. This study lays a solid foundation for the furtherfusion between Building Information Model and finite element analysis.

38. An adaptive-passive retuning device for a pendulum tuned mass damper considering massuncertainty and optimum frequency(Published in Structural Control Health Monitoring, 2019, 26: e2377)

An adaptive-passive retuning device for a pendulum tuned mass damper considering massuncertainty and optimum frequency

WANG Liangkun, SHI Weixing, LI Xiaowei, ZHANG Quanwu and ZHOU Ying*

ABSTRACT: A tuned mass damper (TMD) is one of the most used structural control devices. However, atraditional TMD has the disadvantage of high sensitivity to frequency deviation and difficulty adjusting thefrequency. The optimal frequency for a TMD is dependent on the structural dominant frequency and theTMD mass ratio. Nevertheless, the actual structural modal mass is difficult to obtain, and the presence of aTMD may interfere with identification of the natural structural frequency. Aiming to control wind-inducedvibration, an adaptive-passive retuning device is developed for a pendulum TMD called an adaptive-passivevariable pendulum TMD (APVP-TMD). When it is time to adjust the pendulum, the mass will first be locked,and the structural frequency in this case is identified through wavelet transformation by an accelerationsensor and a microcontroller. It is found that this is actually the optimal frequency for the TMD. Then, astepper motor will adjust the length of the pendulum under the guidance of the microcontroller. Theeffectiveness of APVP-TMD is verified through both discrete and continuous models. For the discrete model,a single-degree-of-freedom primary structure coupled with an APVP-TMD is presented as an experimentwith analysis comparison, and a five-degree-of-freedom primary structure coupled with an APVP-TMD isproposed as a numerical simulation. For the continuous model, a wind-sensitive concrete chimney iscontrolled by an APVP-TMD as a case study. The results all show that the APVP-TMD can identify theoptimal frequency and retune itself effectively, and the retuned TMD has better vibration control than themistuned one.


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39. Random field model for crowd jumping loads(Published in Structural Safety, 2019, 76, 197-209)

Random field model for crowd jumping loadsXIONG Jiechen and CHEN Jun

ABSTRACT: A reliable model for crowd jumping loads is a prerequisite to an accurate prediction of along-span structure’s response when subjected to crowd motion triggered by music and other mass appealevents. Because of the lack of crowd jumping experimental data, crowd jumping load models are scarce withfew data available on this type of synchronisation among people. Inspired by the random field model ofearthquake excitations, this study attempts to develop a random field model for crowd jumping loads basedon extensive records from unique crowd jumping load experiments. A framework for the random field modelof crowd jumping is first proposed, in which auto-power spectral density (PSD) and cross-PSD functions ofindividual and group jumping loads are defined. The auto-PSD was obtained by updating a model in aprevious study. Experiments were conducted on a jumping group of 48 persons using a 3D motion capturetechnology. A cross-PSD model for any two persons in a jumping group was then developed based on theexperimental data. Having obtained a PSD matrix for crowd jumping, the structural response could then bepredicted by the stochastic vibration theory. Finally, the feasibility of the model was verified by comparingthe measured responses of an existing floor with the prediction responses using the proposed model.

40. Collapse fragility analysis of self-centering precast concrete walls with different post-tensioningand energy dissipation designs(Published in Bulletin of Earthquake Engineering, 2019, 17(6): 3593-3613)

Collapse fragility analysis of self-centering precast concrete walls with differentpost-tensioning and energy dissipation designs

WU Hao, ZHOU Ying* and LIU Wenguang

ABSTRACT: Self-centering precast concrete walls have been known as an efficient low-damage lateralforce resisting system for use in seismic regions. Previous studies have mainly focused on investigating thehysteretic behavior of the system through experimental and numerical simulation. This paper evaluates theinfluences of different post-tensioning (PT) and energy dissipation (ED) designs, which can be uniquelycontrolled by designers, on the collapse performance of self-centering precast concrete walls. Additionally,influences of different response reduction factors (R) and collapse criterion during design and analysis arealso examined. For this respect, an example four-story self-centering precast wall building was designed andsimulated using the numerical model verified according to reported test data. A total of eight different designsare considered for the example building with varying parameters of PT and ED designs, and R values. Theanalytical models are then subjected to a suite of 44 ground motions with each scaled up until the collapseoccurs. The fragility curves are generated using the incremental dynamic analysis data, and the results arethen used for collapse risk assessment in accordance with FEMA P695 procedure. The evaluation resultsshow that ED designs have more influence than PT designs to the overall collapse fragility of self-centeringprecast walls. Nevertheless, all the prototype walls in this study are proved to have acceptably lowprobabilities of collapse, which is required by the design code.


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41. Modelling unbonded prestressing tendons in self-centering connections through improvedsliding cable elements(Published in Engineering Structures, 2019, 108: 809-828)

Modelling unbonded prestressing tendons in self-centering connectionsthrough improved sliding cable elements

GAO Wenjun and LU Xilin*

ABSTRACT: The behavior of prestressing tendons essentially affects the seismic responses of self-centeringstructures via providing restoring forces and controlling residual deformations. Conventionally, trusselements are chosen to model prestressing tendons when investigating the dynamic behavior of self-centeringconnections. However, truss elements fail to capture the piecewise configuration of prestressing tendons andunderestimate the axial forces when self-centering connections are subject to large rotations. In order toanalyze this error, two mathematical models are proposed for typical beam-to-column connections andcolumn-to-base connections, respectively. To circumvent the drawbacks of truss elements, sliding cableelements based on rotated engineering strain are derived to modelling prestressing tendons in self-centeringconnections. Finally, numerical examples are presented to validate the effectiveness and accuracy of theproposed modelling method.

42. Dynamic Response of Concrete Frames Including Plain Ductile Cementitious Composites(Published in Journal of Structural Engineering, 2019, 145(06): 04019042)

Dynamic Response of Concrete Frames Including Plain Ductile Cementitious CompositesYU Jiangtao, YE Junhong, ZHAO Bin*, XU Shilang,WANG Bin and YU Kequan

ABSTRACT: Ultrahigh ductile cementitious composites (UHDCC) developed by the authors has the tensilestrain capacity up to 10%. Considering UHDCC has deformability close to steel used for the reinforcement ofthe concrete, the authors tried to study the feasibility of using plain UHDCC in civil engineeringconstruction. In the present study, shaking table tests were conducted on two one-quarter-scale two-storyframe models. One was a reference frame made of reinforced concrete (RC), while the other was a frame, ofwhich all the seismic-vulnerable parts were made of plain UHDCC and the rest parts were inherited from thereference RC frame. The RC frame and UHDCC frame were exposed to a series of scaled earthquakes withthe peak ground acceleration ranging from 0.105g to 1.178g. The seismic capacities of two frames wereevaluated in terms of damage pattern, interstory shear-drift behavior and residual drift. It is indicated that theUHDCC frame had a similar seismic resistance capacity to the reference RC frame and performed even betterin vibration control. According to the acquired dynamic characteristics and tensile strain, a preliminarilyexplanation was given to the seismic performances of the UHDCC frame. Finally, according to the relevantprovisions in various seismic codes, the seismic performance level of the UHDCC frame was estimated.


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43. Seismic performance of flat plate structure with steel capital(Published in ACI Structural Journal, 2019, 116(2): 221-232)

Seismic performance of flat plate structure with steel capitalWANG Lu, XUE Yantao, WANG Cuikun and LU Xilin*

ABSTRACT: The flat plate system, as a popular structure in concrete buildings, still requires improvementin slab-column connections, which are the most vulnerable areas from the point of view of safety. Over thelast few decades, various methods of shear reinforcement have evolved around the world. However, thehysteretic performance and bearing capacity of those methods may not provide absolute guarantees. Theconventional concrete capital referred to herein resembles a truncated pyramid, which has the disadvantage ofrequiring a large space. This paper proposes a new technique- steel capital, which applies steel plates,channel steel, and shear bolts. An experiment of three specimens-one with conventional concrete capital, onewith steel capital, and one control specimen- was conducted. The failure mode, hysteretic loops, skeletoncurve, bearing capacity, stiffness, ductility, and deformation of the three specimens are presented in thispaper: The results indicate that the steel capital can effectively increase the bearing capacity and stiffness ofthe slab-column structure. Steel capital should be considered in the strengthening and design of slab-columnstructures.

44. Experimental study of the hysteretic behaviour of corrugated steel plate shear walls and steelplate reinforced concrete composite shear walls(Published in Journal of Constructional Steel Research, 2019, 160: 136-152)

Experimental study of the hysteretic behaviour of corrugated steel plate shear walls andsteel plate reinforced concrete composite shear walls

WANG Wei*, REN Yingzi, LU Zheng, SONG Jiangliang, HAN Bin and ZHOU Ying

ABSTRACT: To examine the seismic performance of steel plate shear walls (SPSWs) and the correspondingsteel plate reinforced concrete composite shear walls (SPCSWs), six 1:2 scale shear wall specimens (flat,vertical and horizontal corrugated SPSWs and the corresponding SPCSWs) are tested. The deformationcapacity and failure modes of the specimens under cyclic loading are studied. The force–displacementhysteretic curves, envelope curves, bearing capacity and displacement values at various stages are obtained.The failure characteristics, deformation and energy dissipation capacity and the stiffness and thecharacteristics of degradation of the bearing capacity are analysed, and the design formulas of the shearingcapacity of corrugated SPSWs and the corrugated SPCSWs are also proposed. The test results indicate thatthe lateral stiffness, ductility and energy dissipation capacity of composite shear walls are all better than thoseof the SPSWs. The lateral force bearing capacity of flat steel plate, vertical corrugated and horizontalcorrugated SPCSW are 176%, 92%, 41% higher than that of the corresponding SPSWs, respectively. Thedisplacement ductility coefficient of flat steel plate, vertical corrugated steel plate and horizontal corrugatedsteel plate composite wall is 1.86, 1.6 and 1.83 times higher than that of corresponding SPSWs, respectively.Due to the mechanical constraints that concrete applies to steel, the initial stiffness of composite shear wallsis considerably higher than that of SPSWs.


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45. Data-driven two-level performance evaluation of eddy-current tuned mass damper for buildingstructures using shaking table and field testing(Published in Computer-aided Civil and Infrastructure Engineering, 2019, 34(1): 38-57)

Data-driven two-level performance evaluation of eddy-current tuned mass damper forbuilding structures using shaking table and field testing

LU Xilin*, ZHANG Qi, WU Weichao and SHAN Jiazeng

ABSTRACT:A computational framework with a two-level performance evaluation is proposed for the tunedmass damper (TMD)-structure system and is implemented for a new eddy-current (EC) TMD in a data-drivenmanner by incorporating the measurements from a shaking table test and real-world field tests. The first levelof evaluation corresponds to the data analysis with classical performance indices, whereas the second levelfocuses on the energy dissipation and exchange behavior in the time domain. Accordingly, two key steps ofphysical modeling and unmeasured response estimation are sequentially presented, and the steps adopt twotypes of energy balance formulations and state-space descriptions for the primary structure and the TMD,respectively. In the case of shaking table test, the momentary and cumulative behavior of energy dissipationand exchange at the second level is systematically revealed, and several key issues are identified forexplaining the observed performance variation and excitation-sensitivity. In the case of field test, thedamping and control performance of the EC-TMD at the real-world scale is investigated with informativeresults using the first level evaluation.

46. Study on self-adjustable variable pendulum tuned mass damper(Published in Structural Design Tall Special Buildings, 2019, 28: e1561)

Study on self-adjustable variable pendulum tuned mass damperWANG Liangkun, SHI Weixing and ZHOU Ying*

ABSTRACT: Pendulum tuned mass damper (PTMD) is usually used to control the horizontal vibration of atall building. However, traditional PTMD is highly sensitive to frequency deviation and difficult to adjust itsfrequency. In order to improve this problem of traditional PTMD and protect a tall building more effectively,a novel PTMD, called self-adjustable variable pendulum tuned mass damper (SAVP-TMD), is proposed inthis paper. On the basis of the acceleration ratio between TMD and primary structure, the SAVP-TMD canretune itself by varying the length of the pendulum according to the improved acceleration ratio-basedadjustment algorithm. PTMD and primary structural accelerations are obtained from two accelerometersrespectively, and the acceleration ratio is calculated in a microcontroller, then, the stepper motor will adjustthe pendulum under the guidance of the microcontroller under a specific harmonic excitation. The improvedacceleration ratio-based adjustment algorithm is proposed and compared to solve the nonconvergent retuningproblem. The SAVP-TMD can be regarded as a passive damper including a frequency adjustment device. Asingle-degree-of-freedom structure model is used to verify the effectiveness of SAVP-TMD through bothexperimental study and numerical simulation. In order to further verify the effect of SAVP-TMD in theMDOF structure, a five-storey structure coupled with an SAVP-TMD is proposed as a case study. The resultsof experiment, simulation, and case study all show that SAVP-TMD can retune itself to the primary structuraldominant frequency robustly, and the retuned PTMD has a better vibration control effect than the mistunedone.


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47. Seismic damage performance levels for concrete encased steel columns using acousticemission tests and finite element analysis(Published in Engineering Structures, 2019, 189: 471-483)

Seismic damage performance levels for concrete encased steel columnsusing acoustic emission tests and finite element analysis

YUE Jianguang, QIAN Jiang*, and Dimitri E. Beskos

ABSTRACT: Concrete encased steel (CES) columns under low-cyclic lateral loading and high axialcompressive ratios were tested using the acoustic emission (AE) monitoring technique to determine theirdamage performance states. These damage performance states include cover concrete cracking, compressivelongitudinal reinforcement yielding, cover concrete crushing or steel flange local buckling, cover concretespalling, longitudinal reinforcement buckling, and core concrete crushing. Using the test results, a fiber finiteelement method was calibrated and used to numerically simulate 486 CES columns under lateral loading anddetermine an empirical expression for the material parameter of the Park-Ang damage model. Use of thismodified Park-Ang model in conjunction with the response databank coming from the numerical analysis ofthe 486 CES columns, finally leads to limit damage values for the damage states of no-damage,minor-damage, medium-damage, serious-damage, and collapse.

48. Loading protocols for qualification testing of BRBs considering global performancerequirements(Published in Engineering Structures, 2019, 189: 440-457)

Loading protocols for qualification testing of BRBsconsidering global performance requirements

AGUAGUINA Mario*, ZHOU Ying* and ZHOU Yun

ABSTRACT: The paper presents a research on testing protocols for seismic performance assessment andqualification of buckling-restrained braces (BRBs). The purpose of the study was to propose new loadingprotocols that consider the most demanding performance requirements available worldwide. In this study,the loading protocols for qualification testing of BRBs prescribed in the codes of four countries/regions,United States, Europe, China, and Japan, plus a non-official Canadian loading protocol, were consulted. Thereview focused on the background and characteristics, such as the maximum deformation amplitude,deformation range, and number of cycles, of each loading sequence. Then, a database composed of 35 BRBspecimens, selected from 16 past experimental studies, was compiled to perform a series of simulations ofquasi-static cyclic tests of BRBs under the five different loading histories. The OpenSees platform was usedto carry out the modeling, calibration, and analyses. The demands imposed to BRBs were evaluated in termsof cumulative inelastic deformation and cumulative dissipated energy. In addition, the cumulativedistribution of the hysteretic energy was defined as a parameter for the assessment of the amplitude-growthrule of the loading protocols. Based on the code review and analyses results, a series of criteria wereestablished and two new loading protocols, GLP-1 and GLP-2, were proposed. Results demonstrated thatboth proposed loading histories impose superior cumulative inelastic demands and showed a goodagreement with the reference cumulative distribution of the hysteretic energy. Thus, they are recommendedas loading protocols for BRB qualification testing with global applicability.


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49. A New Family of Explicit Model-Based Integration Algorithms for Structural Dynamic Analysis(Published in International Journal of Structural Stability and Dynamics, 2019, 19(6): 1950053)

A New Family of Explicit Model-Based Integration Algorithms forStructural Dynamic Analysis

FU Bo*, FENG Decheng and JIANG Huanjun

ABSTRACT: A new family of explicit model-based integration algorithms for solving the equations ofmotion for linear and nonlinear systems is developed. These algorithms are also known asstructure-dependent algorithms because the integration parameters are functions of the complete model of thestructural system. A variety of numerical properties of the proposed algorithms, including consistency andlocal truncation error, stability, numerical dispersion and energy dissipation, overshooting, and frequencyresponse under arbitrary excitation, are investigated using the discrete control theory and amplificationmatrix for linear elastic systems. In addition, the discrete control theory is applied for assessing the stabilityof the proposed algorithms for nonlinear structural systems. It is observed that the proposed algorithmsexhibit the same numerical characteristics as the well-known Newmark family of integration algorithms.Compared with three existing model-based integration algorithms, i.e. the Chen-Ricles, modifiedChen-Ricles, and Gui's algorithms, the proposed algorithms possess more general and versatile numericalfeatures. As a result, the new family of explicit model-based integration algorithms can be potentially used tosolve complicated linear and nonlinear structural dynamics problems.

50. Shaking table tests and numerical analysis of an over-track multi-tower building(Published in Structure and Infrastructure Engineering, 2019, 15(2): 230-243)

Shaking table tests and numerical analysis of an over-track multi-tower buildingZHOU Ying, CHEN Peng, ZHANG Lixun, WANG Chengyou, and LU Zheng*

ABSTRACT: This article aims to investigate the seismic performance of a four-tower (frame-shear wall)building with a large frame podium at bottom sitting on a metro depot through shaking table test andnumerical simulations. Technical problems generally exist in this type of buildings due to irregularity inelevation and plan, tower offset, and structural transfer. These problems bring challenges to engineers whenanalysing and predicting dynamic responses under earthquakes which is crucial for structural safety. Toevaluate the seismic performance of the building, a comprehensive study which includes a shake table test ofthe scaled model and time history analyses using a finite-element model is conducted. The shake table testmodel is designed based on the similitude law with a 1:40 scale. The dynamic characteristics, crackingpattern, failure mechanism, as well as maximum acceleration and deformation response are investigated. Thecorresponding finite-element analysis shows a good agreement with experimental results. It is concluded thatthis type of building can achieve the predefined performance objectives with well-behaved transfer floors.Shear failure at weak story is considered as a main failure mode of the structure. The whipping effect ofstories on the top of structure is remarkable. There is no severe damage in steel reinforced concrete beams.Finally, some design suggestions are also proposed to improve the seismic performance of this type ofbuildings.


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51. Hysteretic energy demand for self-centering SDOF systems(Published in Soil Dynamics and Earthquake Engineering, 2019, 125)

Hysteretic energy demand for self-centering SDOF systemsZHOU Ying*, SONG Ge and TAN Ping

ABSTRACT: The objective of this study is to introduce a procedure for determining the hysteretic energydemand for self-centering single-degree-of-freedom (SDOF) systems with typical flag-shaped hystereticmodels considering the influences of the structural characteristics. Based on nonlinear dynamic time historyanalyses using a series of representative earthquake records that have been carefully selected, therelationship between the hysteretic energy demand and structural parameters is investigated. Subsequently,the spectra of the ratio of the hysteretic energy EH to the input energy EI, denoted as the EH/EI spectra, areproposed. The results indicate that ground motion types have little influence on the EH/EI spectra. However,both structural features, including energy ratio, damping ratio, and ductility factor, and the initial period ofsystems, play a significant role in the determination of the EH/EI spectra. The proposed approach can beused to predict the hysteretic energy demand for self-centering SDOF systems.

52. Mechanical model of a hybrid non-linear viscoelastic material damping device with itsverifications(Published in Frontiers in Materials, 2019, 6: e33)

Mechanical model of a hybrid non-linear viscoelastic material damping devicewith its verifications

ZHOU Ying*, CHEN Peng and GONG Shunming

ABSTRACT: This paper proposes a new viscoelastic (VE) material damping device with hybrid non-linearproperties. Compared with traditional linear material dampers, the new non-linear VE material dampingdevice is characterized by its better energy dissipation and deformation capability. The series performancetests of the VE device are conducted, based on which the sources and variation law of materialnon-linearities are analyzed. Five aspects of material non-linearities are summarized, including the shapechange of hysteresis loop caused by phase difference, the initial stiffness caused by large loading rate, thesoftening effect caused by high temperature and fatigue, and the softening and stiffening effect under largestrain deformation. A mechanic model for this device is proposed which considers multiple non-lineareffects of the material. For the verifications of the proposed mechanic model, a shaking table test on a steelframe equipped with the new VE devices is designed and performed. Based on the proposed mathematicmechanic model, the numerical mechanic model is implemented in the OpenSees software. The accuracy ofthe mechanic model is firstly verified by comparing the performance tests data with the simulation results.Then the numerical model is also used to calculate the time history response of the shake table tested steelframe under earthquake loading. It is concluded that the mechanic model can well-depict several non-linearmaterial behaviors of the new VE device, and the corresponding numerical model created in the open sourcecalculation platform is reliable to be used to calculate non-linear time history response of a structureequipped with the new VE material damping devices.


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53. Comparative studies of vibration control effects between structures with particle dampers andtuned liquid dampers using substructure shake table testing methods(Published in Soil Dynamics and Earthquake Engineering, 2019,121: 421-435)

Comparative studies of vibration control effects between structures with particle dampersand tuned liquid dampers using substructure shake table testing methods

FU Bo, JIANG Huanjun and WU Tao*

ABSTRACT: This paper compares the vibration control performance of particle dampers (PDs) and tunedliquid dampers (TLDs) by using the up-to-date substructure shake table testing (SSTT) method. Inimplementing the SSTT, three representative model-based integration algorithms, whose algorithmicparameters are functions of the complete model of the structure system to enable unconditional stability tobe achieved within the framework of an explicit formulation, are adopted. The experimental procedures ofthe SSTT methods using the three integration algorithms are presented. The SSTT system of thesingle-degree-of-freedom (SDOF) structures with PDs/TLDs is constructed and verified by comparing theexperimental results of the SSTTs and the corresponding complete structure shake table tests. The vibrationreduction effects of PDs and TLDs with the same mass ratio are investigated and compared by conducting aseries of SSTTs of the SDOF systems with such devices under the excitation of ground motion. Theinfluences of mass ratio, damping ratio and structural frequency on control efficiency of PDs and TLDs arestudied. The results from the parametric analyses demonstrate that all the aforementioned factors havesignificant impacts on the vibration control performance of both dampers. Most experimental resultsindicate that the PDs have better vibration control performance than the counterpart TLDs.

54. Analytical and numerical investigation of quasi-zero stiffness vertical isolation system(Published in Journal of Engineering Mechanics, 2019, 145(6): 04019035)

Analytical and numerical investigation of quasi-zero stiffness vertical isolation systemZHOU Ying, CHEN Peng and MOSQUEDA Gilberto*

ABSTRACT: A novel nonlinear isolation system designed for buildings is proposed to isolate vibrations inthe vertical direction. The system is characterized by quasi-zero stiffness (QZS) obtained by combininglinear springs in parallel with disk springs having nonlinear stiffness, including a region with negativestiffness. Static analysis was first applied to establish the force-displacement relation of the bearings andthen determine the dynamic equations of motion. Two approximate analytical methods, the average method(AM) and harmonic balance method (HBM), were applied to solve this nonlinear vibration problem, andtheir suitability was examined. Based on the theoretical response, the transmissibility function was definedto gain insight into the system’s dynamic characteristics and evaluate the isolation properties. The resultingcurves show that the QZS system can be effective for vertical isolation, with results dependent on externalinput magnitude and the damping level. Larger-amplitude excitation and higher damping level tend toincrease the isolation starting frequency above which the transmissibility reduces the vibration of thesuperstructure. Finally, the nonlinear transmissibility curves were compared with equivalent linear curves,and a numerical comparison between a traditional building and a QZS vertically isolated building underseismic excitations was conducted. The comparison revealed significant advantages to adopting the QZSsystem in vertical isolation.


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55. Confinement effect of concrete-filled steel tube columns with infill concrete of different strengthgrades(Published in Frontiers in Materials, 2019, 6: 71)

Confinement effect of concrete-filled steel tube columns with infill concrete ofdifferent strength grades

HE Liusheng, LIN Siqi and JIANG Huanjun*

ABSTRACT: Concrete-filled steel tube (CFST) columns are increasingly used in composite construction.Under axial compression, the steel tube will sustain partial axial force and meanwhile provides theconfinement to the in fill concrete. The high axial strength capacity of CFST columns is largely related tothe confinement provided by the steel tube. Extensive studies on CFST columns have been conducted.Nevertheless, how to quantify the efficiency of confinement effect in CFST columns using concrete withdifferent strength grades is still missing. To address this issue, a series of compressive loading tests onCFST columns were conducted in present study. The variable parameters studied include concrete strengthand diameter-to-thickness ratio of the steel tube. Six CFST stub columns in total were designed and testedunder uniaxial compression. Axial strength, stress state in the steel tube, confined concrete strength andconfining pressure acting on the in fill concrete were carefully investigated. Test results show that theconfinement factor (defined as the ratio of the nominal strength of empty steel tube to that of the unconfinedconcrete) is the most dominant factor influencing the confinement effect, and a larger confinement factorgives higher confinement effect. The low-strength concrete exhibits better performance of ductility andconfinement compared with the high-strength concrete. The index of equivalent confining pressure wasused to quantify the level of passive confinement provided by the steel tube in CFST columns. Based on thetest results, a method to quickly quantify the confining pressure provided by the steel tube was proposed.

56. Similitude theory for scaled friction pendulum bearings for shaking table experiments(Published in Soil Dynamics and Earthquake Engineering, 2019, 121: 399-404)

Similitude theory for scaled friction pendulum bearings for shaking table experimentsREN Xiangxiang, LU Wensheng*, MOSALAM Khalid M. and XU Weiyang

ABSTRACT: Scaled models of friction pendulum bearings (FPBs), which require a similitude design basedon a set of scaling laws, are typically employed in shaking table experiments to investigate the seismicbehavior of the models. In this study, scaling laws for scaled FPBs are developed to determine the physicalparameters of their models. Then, an equivalent method for the distribution of scaled FPBs in the modelisolation layer is proposed for scaling cases in which fewer FPBs are arranged in the model than in theprototype. In addition to an accurate simulation of the global seismic response of the prototype isolationlayer, the proposed equivalent method also aims to simulate the possible worst-case loading conditions of anindividual FPB in a prototype. A model of an FPB-isolated space truss on top of four towers was scaled,manufactured and tested on a shaking table. A comparison of the seismic response of the global isolationlayer and the individual FPB between the model and the prototype demonstrates the effectiveness of thedeveloped theory.


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57. Experimental study of seismic response reduction effects of particle damper using substructureshake table testing method(Published in Structural Control & Health Monitoring, 2019, 26(2): e2295)

Experimental study of seismic response reduction effects of particle damper usingsubstructure shake table testing method

FU Bo, JIANG Huanjun and WU Tao*

ABSTRACT: In order to evaluate the effectiveness of particle dampers (PDs) on seismic responsereduction of structures, a series of substructure shake table tests have been conducted. A new family ofexplicit model-based integration algorithms is used to develop the substructure shake table testing (SSTT)method. To implement the SSTT method, a testing system on the basis of the Quanser shake table II isconstructed. The effectiveness and accuracy of the proposed SSTT method and the testing system areverified by comparing the results of complete structure shake table tests and the corresponding substructureshake table tests. Mass ratio, which is defined as the ratio of the damper mass to the structural mass andstructural damping ratio are taken as two main parameters in the parametric analyses. Twelve cases of PDs,which are categorized into three patterns, with different materials, sizes, and amounts of particles areselected as the experimental substructures. The substructure shake table test results indicate that the overallseismic response reduction effects of three different types of PDs are very close with same mass ratio. Twoseismic response reduction ratios in terms of reducing peak and root-mean-square relative structuraldisplacements are defined to quantify the seismic response reduction effects of the dampers. It can beconcluded from the experimental studies that both seismic response reduction ratios increase as the massratio increases and decreases as the structural damping ratio increases.

58. Damage Deformation of Flexure-Yielding Steel-Reinforced Concrete Coupling Beams:Experimental and Numerical Investigation(Published in Advances in Civil Engineering, 2019, 15(2): 230-243)

Damage Deformation of Flexure-Yielding Steel-Reinforced Concrete Coupling Beams:Experimental and Numerical Investigation

LI Yinghui, JIANG Huanjun* and YANG T. Y.

ABSTRACT: SRC coupling beams offer many significant advantages, including the reduction in sectiondepth, reduced congestion at the wall boundary region, improved degree of coupling for a given beamdepth, and improved deformation capacity. In this paper, 7 half-scale flexure-yielding SRC coupling beamsdesigned according to Chinese approach have been tested under cyclic loads. Detailed parameters such asaspect ratios, steel reinforcement ratios, and steel flange-web ratios were systematically studied, and thedamage behavior of SRC coupling beams were presented in this paper. The test results show that the aspectratio, steel ratio, and steel flange-web ratio have great influence on the damage behavior of SRC couplingbeams. Three-dimensional nonlinear finite element models were constructed and benchmarked throughcomparison with test results for both global and local damage deformation behavior. Based on the materialdamage and strength degradation, four performance levels were defined and corresponding chord rotationlimits were obtained through the verified numerical analysis.


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59. Study of an innovative graded yield metal damper(Published in Journal of Constructional Steel Research, 2019, 160: 240-254)

Study of an innovative graded yield metal damperCHEN Yun, CHEN Chao, Jiang Huanjun*, LIU Tao and WAN Zhiwei

ABSTRACT: Metal dampers have been widely used to improve the seismic performance of the buildingstructure. However, conventional metal dampers only possess one yield point and cannot protect thestructure efficiently under earthquakes of different intensities. A new type of metal damper composed of twoannular metal dampers with different sizes is proposed in this paper. It is a graded yield metal damperhaving two yield points, which can be used to reduce the responses of the structure efficiently underearthquakes of different intensities. Firstly, the mechanical properties of single annular metal damper, suchas the failure mechanism, hysteretic behavior and anti-fatigue performance, are investigated by cyclicloading tests. The test results show that the annular metal dampers possess large deformation capacity andenergy-dissipation capacity as well as excellent anti-fatigue performance. The calculation formulae arederived to determine major mechanical parameters of the damper. The theoretical results obtained by usingthe proposed calculation formulae are in good agreement with experimental results. Cyclic loading tests arecarried out on the graded yield metal damper. The yielding process of the graded yield metal damper issimulated using the ABAQUS program. The trilinear kinematic hardening model is adopted to simulate thehysteretic behavior of the damper. Nonlinear time history analyses are carried out to compare the responsesof a conventional reinforced concrete (RC) moment-resisting frame structure with that of the structureinstalled with the graded yield metal dampers under three levels of earthquakes using SAP2000. The resultsindicate that the seismic performance of the structure installed with the graded yield metal dampers underall levels of earthquakes is improved significantly. The graded yield metal dampers are more effective indisplacement control of reinforced concrete moment-resisting frame structure in comparison with singleyield point metal dampers.

60. Peak response prediction for RC beams under impact loading(Published in Shock and Vibration, 2019, 6813693)

Peak response prediction for RC beams under impact loadingZHAO Wuchao,QIAN Jiang* and JIA Pengzhao

ABSTRACT: In this paper, a novel and simple method for predicting the peak response of RC beamssubjected to impact loading is proposed. The theoretical basis for calculating the peak impact forceoriginates from the contact law, the principle of conservation of energy, the impulse-momentum theorem,and the wave theory. Additionally, the conventional beam theory, in conjunction with the well-knownlayered-section approach, is utilized to obtain the force-deflection relationship of the RC beam.Subsequently, by taking into account the strain rate effect, the maximum midspan deflection of RC beamsunder impact loading is determined based on the conservation of energy approach. A comparison with 143impact tests has shown that the proposed method is able to estimate the maximum midspan deflection of RCbeams under impact loading with high accuracy. The prediction of the peak impact force is shown to beslightly overestimated, which however can be used in the anti-impact design to preclude the shear failurenear the impact point.


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61. Study on mechanical properties of high damping viscoelastic dampers(Published in Advances in Structural Engineering, 2019)

Study on mechanical properties of high damping viscoelastic dampersCHEN Yun, CHEN Chao, MA Qianqian, JIANG Huanjun* and WAN Zhiwei

ABSTRACT: The mechanical properties of the viscoelastic damper made of high damping rubber producedin China are investigated in order to provide the basis for its application. At first, the test on materialproperties of high damping rubber is conducted. The Mooney–Rivlin model, the Yeoh model and the Pronyseries are applied for simulating the nonlinear behavior of the high damping rubber with the aid of softwareABAQUS. Then, three viscoelastic dampers with different sizes are tested under cyclic loading. The effectsof strain amplitude and loading frequency on hysteretic behavior of dampers are analyzed. Viscoelasticdampers possess large deformation capability, stable energy-dissipation capacity and good fatigue-resistingproperty. The effect of strain amplitude is much more significant than loading frequency. The hystereticbehavior of the dampers is simulated by the Bouc–Wen model and the model of the equivalent stiffness anddamping, respectively. The prediction results by using the Bouc–Wen model are in good agreement with theexperimental results, which indicates that the Bouc–Wen model is applicable to simulate the mechanicalproperties of high damping viscoelastic dampers with a wide range of shear strain. As to the model ofequivalent stiffness and damping, it has the advantages of clear concept and simple calculation. However,the good accuracy of prediction can be obtained only when the shear strain is not greater than 60%.

62. Earthquake resilient RC walls using shape memory alloy bars and replaceable energy dissipatingdevices(Published in Smart Materials and Structures, 2019, 28(6): 065021)

Earthquake resilient RC walls using shape memory alloy bars andreplaceable energy dissipating devices

WANG Bin, ZHU Songye*, ZHAO Junxian and JIANG Huanjun

ABSTRACT: This study presents a novel precast reinforced concrete (RC) wall system using shapememory alloy (SMA) bars and replaceable energy dissipating (ED) devices to achieve earthquake resilience(hereafter referred to as SMA-based RC wall). The major advantages of this structural system include (1)self-centering (SC) capability provided by the unbonded superelastic SMA bars used in the bottomboundary zones of the wall, (2) concentrated energy dissipation and damage in the replaceable steel angles,and (3) an earthquake resilient design that requires minimal repair even after strong earthquakes. Thestructural details and design considerations of the SMA-based RC wall were first introduced. Subsequently,the mechanical behavior of the SMA bars and ED angles was investigated through cyclic loading tests. Theseismic performance of the SMA-based RC walls was computationally investigated using variousparameters of interest in seismic applications and evaluated in terms of strength, stiffness, and SC and EDcapabilities. The proposed SMA-based RC walls exhibited satisfactory and stable flag-shaped hystereticloops with excellent SC and satisfactory ED capabilities. Compared with conventional RC walls, theproposed SMA-based RC walls provide a promising solution for high-performance structural systemsrequired by modern resilient and sustainable civil infrastructure.


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63. Probabilistic assessment of upgraded rocking cores-moment frames with supplementalself-centering energy dissipation devices(Published in Journal of Earthquake Engineering, 2019, 1-25)

Probabilistic assessment of upgraded rocking cores-moment frames with supplementalself-centering energy dissipation devices

WU Dayang, LU Xilin* and ZHAO Bin

ABSTRACT: An upgraded rocking cores-moment frame (RCMF), aimed to improve the RCMF from lifesafety to seismic resilience, is proposed in this article by equipping the rocking cores with replaceableself-centering energy dissipation devices. Its seismic performance is assessed within a probabilisticframework, which treats maximum interstory drift ratio (MD) and residual interstory drift ratio (RD) as acombined engineering demand parameter. Results indicate that the upgraded RCMF demonstrates anoutstanding performance in reducing MD, RD and their corresponding deviations, mitigating the driftconcentration, especially in eliminating the RD, which highlights its potential to achieve seismic resilience.

64. Collapse resistance of composite framed-structures considering effects of slab boundaryrestraints(Published in Journal of Constructional Steel Research, 2019, 158: 171-181)

Collapse resistance of composite framed-structures considering effects ofslab boundary restraints

ZHANG Jingzhou, LI Guoqiang ⁎, JIANG Jian, ZHANG Wenjin

ABSTRACT: This paper analytically deals with the collapse resistance of composite framed-structuresconsidering effects of slab boundary restraints. The collapse resistance of composite framed-structures dueto different interior-edge(IE) column losses are investigated. The IE columns refer to the interior columnsdirectly adjacent to the exterior columns, among which those nearest to corner columns are defined asinterior-edge-corner (IEC) columns and the rests are interior-edge-intermediate (IEI) columns. Theresponses of main structural members including reinforced concrete slabs, steel beams and steel columns atlarge deflections are fully accounted for. The collapse resistance of composite framed-structures for ageneral interior (GI) column loss scenario has been previously studied. Three contributions to internalenergy dissipations were considered, including the elongations of rebar and steel beams, the tensileforce-induced additional bending moments, and the bending moments along yield lines of the slab. For IEcolumn loss scenarios, however, besides the original three energy dissipations, contributions due to thedeformation of the peripheral beams and edge columns are included. The detrimental effect of the lateraldisplacement at the top of edge columns on the energy dissipations due to the elongation of rebar and steelbeams is also accounted for. The reasonability and reliability of the analytical method are verified againstvalidated numerical analyses. The resistance-displacement curves of structures due to IEI and IEC columnlosses are compared. It is confirmed that for the IEC column loss scenario, a structure has the leastprogressive collapse resistance due to its weakest boundary conditions. Due to the existence of the concreteslab, the differences between the progressive collapse resistance of structures for IEI and IEC column lossscenarios are mitigated.


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65. High-speed running maglev trains interacting with elastic transitional viaducts(Published in Engineering Structures, 2019, 183: 562-578)

High-speed running maglev trains interacting with elastic transitional viaductsXU Youlin, WANG Zhilu, LI Guoqiang, CHEN Suwen and YANG, Yeongbin

ABSTRACT: This paper presents a general framework for the dynamic analysis of high-speed maglevtrains running on elastic transitional viaducts, a complicated problem that lacks an efficient analysis tool.Unlike the straight and circular tracks, both the curve radius (CR) and height difference (HD) between theouter and inner rails vary along the transitional track. To start, the motion of each vehicle of the trainrunning over a transitional track is expressed by a set of trajectory coordinates, with their orientations givenin the Euler angles as functions of the CR and HD. The elastic transitional viaduct is simulated by finiteelements in the global coordinates. For the maglev trains, the electromagnet force-air gap model is used toaccount for the interaction and coupling effect between the moving vehicles and supporting viaduct. Byapplying the proposed framework to the Shanghai maglev line (SML), the dynamic responses of the maglevvehicles running on the transitional viaduct are studied and compared with those on the straight and circularviaducts. Moreover, the effects of transitional track length and cant deficiency on the coupled system areinvestigated. The results show that for vehicles running on the transitional track, the levitation forces andvehicle’s angular velocity are highly related to the rate of change of HD of the track. The length of thetransitional viaduct affects significantly all the vehicle’s responses. The increase of deficient cant anglecauses a sharp increase in the responses of the transitional viaduct in both the radial and rotationaldirections.

66. Collapse resistance of RC beam-slab subassemblies due to column loss at large deflections(Published inMagazine of Concrete Research, 2019, 71(12): 647-663)

Collapse resistance of RC beam-slab subassemblies due to column lossat large deflections

ZHANG Jingzhou, LI Guoqiang* and JIANG Jian

ABSTRACT: This paper proposes an energy-based method to theoretically determine the collapseresistance of reinforcedconcrete (RC) beam–slab subassemblies subject to a middle column loss at largedeflection. It considers the contributions to internal energy dissipation due to extension of rebar in the slaband beams, the additional resultant bending moment from membrane forces in the slab and catenary tensileforces in beams, and the sectional bending moment at plastic hinges of beams and along yield lines of slabs.Furthermore, the effect of tensile forces on the sectional bending moment of the slab and beams is alsoaccounted for. The effectiveness and accuracy of the proposed method are validated against available testresults. The proposed method is found to produce accurate predictions on the collapse resistance of thesubassemblies, as well as capture the main feature of mechanism of the subassembly at large deflections. Itis concluded that the energy dissipation due to the extension of rebar and additional resultant bendingmoment significantly contribute to the resistance of subassemblies at large deflections. The interactionbetween membrane forces and bending moment of the beam and slab sections has a detrimental effect onthe collapse resistance. Neglecting this effect will overestimate the collapse resistance for the subassembly.


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67. Slip factors of high strength steels with shot blasted surface(Published in International Journal of Constructional Steel Research, 2019, 157: 10-18)

Slip factors of high strength steels with shot blasted surfaceWANG Yanbo, WANG Yuanzuo, CHEN Kun and LI Guoqiang*

ABSTRACT: In order to evaluate the performance of the slip critical bolted connection of HSS members,30 specimens fabricated from high strength steel (HSS) (Q550, Q690 and Q890), are tested to investigatethe slip factors of shot-blasted surface and rusted surface after blasting. For comparison, a group ofspecimens fabricated from mild steel Q345 are tested as well. In order to investigate the effect of the steelstrength grade on slip factor, the values of hardness, roughness and capacity of plastic deformation of steelswith different strength grades are also tested and analyzed. Based on experimental results and frictiontheory, it is found that with the same blasting treatment, the surface roughness tends to decrease with theincrease of steel hardness, which induces the decreasing of the slip factor. Based on the friction mechanism,the slip factor is not only decided by surface roughness, but also can be affected by the capacity of plasticdeformation of the contacting materials. With the increasing of plastic deformation capacity of the steel, theslip factor tends to be higher. According to the test results, the suggested slip factor of HSS specimens withblasted surfaces is 0.40. Moreover, for the specimens with rusted surface after blasting, there may be anincrement in the slip factor owing to the increased surface roughness by rusting. However, the positiveinfluence of rusting on the slip factor is not recommended to be considered in the connection design due toits instability. Therefore, the recommended slip factor of the specimen with rusted surface after blastingtakes the value of 0.40 as well.

68. Development of Pressure-Impulse Diagrams for Framed PVB-Laminated Glass Windows(Published in International Journal of Structural Engineering, 2019, 145(3): 04018263)

Development of Pressure-Impulse Diagrams for Framed PVB-Laminated Glass WindowsCHEN Suwen*, CHEN Xing, LI Guoqiang and LU Yong

ABSTRACT: This paper investigates isodamage criteria for framed PVB (polyvinyl butyral) laminatedglass panels subjected to blast load. Isodamage criteria are presented in the form of pressure-impulse (P-I)diagrams, and a methodology for the generation of the P-I diagrams for laminated glass was developedbased on numerical simulation studies and the energy method. Three damage levels were classified inaccordance with the conditions identified in standards, namely (1) the glass crack limit, (2) the PVB rupturelimit, and (3) overall detachment with a specific velocity after the PVB ruptures. Based on nonlinearfinite-element analysis, the governing failure modes of the glass panel in both impulsive and quasi-staticregions for each damage level were identified and the corresponding deflection functions were determined.A simplified PVB tensile bar model is proposed to describe the local tensile failure of PVB laminated glasscorresponding to Damage Level III under impulsive loading. The pressure and impulse asymptotes offramed PVB-laminated glass for different damage levels were derived using the energy balance principle.The proposed method was validated through comparison with published experimental data and furthernumerical results. This method can provide a reference for engineering design and hazard estimation offramed PVB-laminated glass against blast loading and can be extended to laminated glazing with otherinterlayers.


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69. Input energy spectra for self-centering SDOF systems(Published in Soil Dynamics and Earthquake Engineering, 2019, 121: 293-305)

Input energy spectra for self-centering SDOF systemsZHOU Ying, SONG Ge, HUANG Shimin and WU Hao*

ABSTRACT: This study proposes a procedure for determining design input energy spectra forself-centering single-degree-of-freedom (SDOF) systems using a characteristic flag-shaped hystereticmodel. The procedure for determining design input energy spectra considers the influence of ground motionfactors, hysteretic models, damping ratios, and ductility factors. First, nonlinear dynamic time historyanalyses are performed using 40 representative ground motion records to establish the relationship betweeninput energy spectra and critical parameters. Based on this, normalized design input energy spectra andrelevant parameters are proposed. The results of this study indicate that the bilinear hysteretic model is notsuitable to accurately predict the input energy spectra for self-centering systems. Meanwhile, both thedamping ratio and ductility factor have a significant influence on the resulting input energy spectrathroughout the entire period range. The proposed procedure can be used to predict earthquake input energyspectra for self-centering SDOF systems.

70. Seismic performance improvement of tension-only-braced frames with Energy-DissipativeRocking Columns(Published in Engineering Structures, 2019, 196: Article 109286)

Seismic performance improvement of tension-only-braced frameswith Energy-Dissipative Rocking Columns

LI Yanwen, LI Guoqiang *, JIANG Jian, WANG Yanbo

ABSTRACT: Steel braced frames consisting of strong beams, weak columns, and tension-only braces(BTFs) have been extensively used in low-rise steel buildings, since it is prefabricated rapidly and iscost-efficient. However, BTFs are vulnerable to soft story failure due to the negligible post-yieldingstiffness of tension-only braces. A novel device of Energy-Dissipative Rocking Column (EDRC) isproposed to improve the seismic performance of BTFs. An EDRC consists of dual hinge supported steelcolumn branches and replaceable steel strip dampers between them. Firstly, the effectiveness of EDRCswere verified through nonlinear time history analyses on benchmark multi-story BTFs using a suite offar-field ground motion records. Secondly, systematic parametric studies are conducted to quantify theeffect of key influencing factors such as stiffness ratio of EDRC to BTF and bending stiffness of columnbranches on the seismic performance improvement of BTF-EDRC systems. The results show that themaximum inter-story drift and inter-story drift concentration under earthquakes as well as the residual driftafter earthquakes can be significantly mitigated by coupling with EDRC. It is found that the maximuminter-story drift ratio can be reduced by 50% when the stiffness ratio of EDRC to BTF reached 1.0. Themost effective stiffness ratio of EDRC to BTF for mitigating the inter-story drift concentration and residualdrift ratio falls in a range of no more than 0.2 and 0.4, respectively.


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71. Experimental study on cyclically-damaged steel-concrete composite joints subjected to fire(Published in Steel and Composite Structures, 2019, 30(4): 351-364)

Experimental study on cyclically-damaged steel-concrete composite joints subjected to fireYE Zhongnan, JIANG Shouchao, Heidarpour Amin*, LI Yingchao and LI Guoqiang

ABSTRACT: Earthquake and fire are both severe disasters for building structures. Sinceearthquake-induced damage will weaken the structure and reduce its fire endurance, it is important toinvestigate the behavior of structure subjected to post-earthquake fire. In this paper, steel-concretecomposite beam-to-column joints were tested under fire with pre-damage caused by cyclic loads.Beforehand, three control specimens with no pre-damage were tested to capture the static, cyclic andfire-resistant performance of intact joints. Experimental data including strain, deflection and temperaturerecorded at several points are presented and analyzed to quantify the influence of cyclic damage on fireresistance. It is indicated that the fire endurance of damaged joints decreased with the increase of damagelevel, mainly due to faster heating-up rate after cyclic damage. However, cracks induced by cyclic loadingin concrete are found to mitigate the concrete spalling at elevated temperatures. Moreover, the relationshipbetween fire resistance and damage degree is revealed from experimental results, which can be applied infire safety design and is worthwhile for further research.

72. Analysis on interstory drift of high-rise residential quasi-megastructure(Published in Advances in Structural Engineering, 2019, 22(7): 1755–1768)

Analysis on interstory drift of high-rise residential quasi-megastructureSUN Feifei, XIAO Ben* and JIN Huajian

ABSTRACT: Based on the superior lateral resistant performance of mega-X layout pattern, the concept ofquasi-megastructure was put forward to introduce quasi-mega mechanism in residential buildings, usingnormal members only, avoiding large architecture space occupation of mega members. Unlike themegastructures that are dominated by their primary structures, the quasi-megastructures mainly realize asynergistic mechanism between the frame structure and quasi-mega braces. In order to investigate itsdeformation mechanism and reduce the lateral stiffness irregularity, a simplified method for evaluatinginterstory drift of high-rise quasi-megastructure was proposed, based on three fundamental assumptions.Thus, the interstory drift formula for any specific layout scheme of quasi-megastructure can be deduced.The formula was validated by different layout schemes. By this method, the interstory drift proportion ofquasi-megastructure was investigated, showing that the interstory drift of a target story mainly consists ofdrift due to rigid body rotation, pure shearing drift, and shear-lag added drift. And the vertical stiffnessirregularity of the original scheme was due to great changes of shear-lag added drift in different neighboringstories. Thereafter, stiffened schemes were proposed, which effectively eliminate the interstory stiffnessirregularity by complementing a quasi-mega cantilever wall of full height. Compared with mega framestructure, the original scheme has a similar overall deformation mechanism, while the properly stiffenedquasi-megastructure scheme behaves quite close to mega braced frame structure, both in deformationmechanism and in structural efficiency.


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73. Local Bearing Capacity of Steel Beams with Corrugated webs(Published in International Journal of Steel Structures, 2019, 19(1): 44-57)

Local Bearing Capacity of Steel Beams with Corrugated websLI Xiaopeng, ZHANG Zhe* and LI Guoqiang

ABSTRACT: Nine specimens were tested to investigate the local bearing capacity of steel beams withcorrugated webs. Then, the infuence of diferent load distribution widths on local bearing capacity wasstudied. Results showed that the failure modes of the specimens were web yielding and changed from brittlefailure to plastic failure at increased distribution width. The ultimate bearing capacities were higher thanthose of steel beams with plate webs. Meanwhile, the loading course, ultimate load and failure modes wereclosely simulated through the fnite element method, and parameter analysis was performed, the result ofwhich verifed the decreased capacity of the sparse waveforms. The design expression of the local bearingcapacity under diferent load distribution widths were obtained on the basis of these results and applied tocrane beams with corrugated webs. The calculated results compared with fnite element analysis andexperimental results suggested the correctness and reliability of the design expression.

74. Stochastic micromechanical predictions for the probabilistic behavior of saturated concreterepaired by the electrochemical deposition method(Published in International Journal of Damage Mechanics, 2019)

Stochastic micromechanical predictions for the probabilistic behavior of saturated concreterepaired by the electrochemical deposition method

CHEN Qing*, Zhu Hehua, J Woody Ju, YAN Zhiguo, JIANG Zhengwu, CHEN Bo*,WANG Yaqiong and FAN Zhihong

ABSTRACT: A stochastic micromechanical framework is proposed to quantitatively characterize theprobabilistic behavior of the mechanical performance of the saturated concrete healed by the electrochemicaldeposition method. Micromechanical model for the healed saturated concrete is presented based on thematerial microstructures, and new multilevel homogenization procedures are proposed to quantitativelypredict the effective properties of the repaired concrete considering the inter-particle interactions. Theevolutions of the deposition products are characterized by non-stationary random process, which isrepresented by Karhunen–Loeve approximations with limited random variables. The probabilistic behaviorfor the effective properties of the repaired concrete is reached by incorporating the maximum entropyprinciple and Monte Carlo simulations. The predictions obtained by the proposed stochastic micromechanicalframework are then compared with the available experimental data, existing models, and commonly usedprobability density functions, which indicate that the presented stochastic micromechanical framework iscapable of describing the electrochemical deposition method healing process, considering the inherentrandomness of the material microstructures. Finally, the influences of the deposition products on theprobabilistic behavior of the repaired concrete are discussed on the basis of the proposed models.


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75. Experimental study on seismic performance of RC frames with Energy-Dissipative RockingColumn system(Published in Engineering Structures, 2019, 194: 406-419)

Experimental study on seismic performance of RC frames withEnergy-Dissipative Rocking Column systemLI Yanwen, LI Guoqiang*, JIANG Jian, WANG Yanbo

ABSTRACT: The conventional reinforced concrete Moment Resisting Frames (MRFs) have suffered fromsoft story failure during major earthquake events. A novel system of steel Energy-Dissipative RockingColumn (EDRC) is proposed to mitigate seismic responses of MRFs. Pseudo-dynamic tests are conductedon large-scale two-story and two-bay reinforced concrete frames, with and without EDRC, respectively. Thepost-earthquake behavior of these two systems is also compared through quasi-static cyclic tests. Theexperimental results show that the presence of EDRC can effectively mitigate the maximum value, residualvalue and inhomogeneous distribution of inter-story drifts, and thus prevent the soft story failure of MRFs.It is found that the maximum and residual inter-story drift of combined MRF and EDRC systems is reducedby 26.0% and 82.0%, respectively, compared to pure MRFs. The inhomogeneous degree of inter-story driftscan be reduced by 25.0% and 11.0%, respectively, in the pseudo-dynamic and quasi-static tests.

76. Dynamic mechanical property experiment of viscous material for viscous damping wall(Published in Frontiers in Materials, 2019, 6:112)

Dynamic mechanical property experiment of viscous material for viscous damping wallSUN Feifei, YANG Jiaqi* and WU Tanye

ABSTRACT: Viscous damping wall (VDW) is an effective velocity-dependent damper, which can dissipateearthquake energy by shear strain of viscous material. The damping force equation of VDW can only beobtained from regression of VDW dynamic test results, as velocity exponent of power-law material can notbe obtained from rheometers. In this study, a Dynamic Sandwich-Type Shear test was designed matchingthe design working conditions of VDW. A series of experiments with different frequencies and strainamplitudes were conducted. Simple data procession methods were proposed to calculate velocity exponentand storage/loss modulus of polymer from experimental data. Comparison with methods adapted from thosefor VDW formula validated that radial linear regression method was proper to separate stress componentsand pivotal point method was accurate to evaluate velocity exponent. The velocity exponents obtainedvaried from 0.8 to 1, with various loading frequency and strain amplitude. Finally, the differences betweenthe results of storage/loss modulus in DSTS test and ARES test were compared. Due to the extrusion effectcaused by engineering working condition, the storage and loss modulus obtained by DSTS test was largerthan the modulus obtained by ARES test.


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77. Cyclic behaviour of bearing-type bolted connections with slot bolt holes(Published in Advances in Structural Engineering, 2019, 22(3): 792-801)

Cyclic behaviour of bearing-type bolted connections with slot bolt holesLI Guoqiang, HOU Zhaoxin, SUN Yingzhi*, GONG Chao and JIANG Jian

ABSTRACT: This article experimentally studies the behaviour of high-strength bolted connections withslot bolt holes under cyclic load to evaluate its seismic performance. A total of six specimens varying in thebolt diameters and pretension are designed and tested. The results show the connections with slot holes havegood energy dissipation capacity. It is found that connections with M30 bolts, of which the hysteretic loopsare fuller, have better energy dissipation capacity than that of M20 bolts connections. With the increase ofnumber of loading cycles, the sliding force of the connections decreases. On the other hand, the ultimatebearing capacity of the connections does not decrease much both for M30 and M20 bolts. As theexperiments proceed, the friction coefficients and the areas of the hysteresis curves decrease in a similartrend because of the smoothing of surfaces. The experimental results indicate the potential application of theconnections with slot bolt holes as dual-function parts in structures to simultaneously provide stiffness andenergy dissipation capacity.

78. A compatible probabilistic framework for quantification of simultaneous aleatory and epistemicuncertainty of basic parameters of structures by synthesizing the change of measure andchange of random variables (Published in Structural Safety, 2019, 78, 76-87)

A compatible probabilistic framework for quantification of simultaneous aleatory andepistemic uncertainty of basic parameters of structures

by synthesizing the change of measure and change of random variablesCHEN Jianbing and WAN Zhiqiang

ABSTRACT: Uncertainty has been attached increasing importance in performance evaluation and reliabilityassessment of engineering structures. However, the logical framework for the quantification of simultaneousaleatory uncertainty and epistemic uncertainty of basic parameters of structures in a compatible probabilisticsense is still not readily available as yet, and the computational efforts are also usually prohibitively large. Inthe present paper, a compatible probabilistic framework is proposed for this purpose. Limited to the epistemicuncertainty that characterizing the uncertainty in aleatory uncertainty, i.e., the uncertainty in the shape orparameters of probability density function of the source random variables, it is found that the quantificationand propagation of aleatory uncertainty is a problem of change of random variables, and the principle ofpreservation of probability holds. For dynamical systems the probability density evolution method (PDEM)can be adopted for this purpose. Whereas, the quantification of epistemic uncertainty is essentially a problemof change of probability measure, and thus the Radon-Nikodym theorem holds. Therefore, synthesizing thechange of measure (COM) and the change of random variables (CRV) will provide a logically clearcompatible framework for the quantification of simultaneous aleatory and epistemic uncertainties. Thenumerical algorithm by changing the assigned probabilities of representative points in the PDEM is thenproposed. A nonlinear equation, the Riccati equation, is investigated to illustrate the proposed method. Theresult is verified by the exact analytical solution. Moreover, a 3-span 10-storey reinforced concrete (RC)frame structure modelled by the finite element method is studied. This exemplifies the quantification ofsimultaneous aleatory and epistemic uncertainties of basic parameters of real-world civil engineeringstructures. The examples demonstrate the effectiveness of the proposed method. Problems to be furtherstudied are also outlined.


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79. Use of energy-dissipative rocking columns to enhance seismic performance buckling-restrainedbraced frames(Published in Journal of Constructional Steel Research, 2019, 159: 548-559)

Use of energy-dissipative rocking columns to enhance seismic performance ofbuckling-restrained braced frames

LI Yanwen, LI Guoqiang *, JIANG Jian, WANG Yanbo

ABSTRACT: Buckling-Restrained Braced steel frames (BRBFs) exhibit well-controlled seismic behaviordue to their excellent lateral load resisting capacity and energy dissipation capacity. However, they alwayssuffer from concentration of inter-storey drifts and excessive residual deformations in weak/soft storiesunder strong earthquakes. A novel system of Energy-Dissipative Rocking Column (EDRC) is proposed inthis paper to improve the seismic performance of multi-storey BRBFs. It consists of dual hinge supportedsteel column branches and replaceable steel strip dampers between them. Nonlinear time historey analysesare conducted on a six-storey prototype BRBFs with EDRCs to investigate the effectiveness of EDRCs onimproving the seismic performance of BRBFs under different levels of earthquakes. It is found that theEDRC can not only mitigate the maximum and residual inter-storey drifts, but facilitate more uniformdistribution of inter-storey drifts. A rational range of EDRC stiffness ratio less than 0.2 is recommended forthe seismic design of BRBFs with EDRCs.

80. Seismic control strategy of a multi-story subway station based on probability density evolutionmethod(Published in International Journal of Computational Methods, 2019, 1940014: 1-22.)

Seismic control strategy of a multi-story subway station based onprobability density evolution method

LIU Zhiqian and CHEN Zhiyi*

ABSTRACT: The method to protect the whole station structure by installing flexible devices at the columnend has been proved to be effective in typical station structures. However, the damping effects andapplication of this method to multi-story subway station structures still need further study. In this paper, astochastic analysis method, probability density evolution method (PDEM), is adopted to estimate thedamping effect of a four-story subway station structure with lead rubber bearings (LRBs) installed in thecentral column. Stochastic analysis results show that the internal forces and plastic energy dissipation ofcolumns installed LRBs are greatly reduced and the reliability is improved. Internal forces and plasticenergy dissipation of columns without the installation of LRBs increase and the reliability decrease. There islittle difference in structural deformation and plastic energy dissipation of structural components when LRBis installed in the middle of the column or at the column ends. When LRBs are installed only in some of thestories, the overall reliability of the structure is lower than that of the structure without LRB. When LRBsare installed in the columns of all stories, the structural reliability is higher than that of the structure withoutLRB. Based on the above results, to obtain better seismic control effect by installing LRBs, the multi-storysubway station structure should be installed with LRBs in the columns of all stories, and LRBs can beinstalled at the upper, middle and lower end of the columns.


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81. Effects of nominal flexibility ratio and shaft dimensionless parameters on the seismic responsecharacteristics of deep shafts(Published in Soil Dynamics and Earthquake Engineering, 2019, 120: 257-261.)

Effects of nominal flexibility ratio and shaft dimensionless parameters on the seismicresponse characteristics of deep shafts

ZHANG Bu and CHEN Zhiyi*

ABSTRACT: With the exploitation and utilization of deep underground space in urban areas, an increasingnumber of deep vertical shafts are being constructed and utilized. In order to understand the seismicresponse characteristics of the deep shafts, the nominal flexibility ratio formula was derived based on thequasi-static method for approximately evaluating the shaft kinematic responses. Three dimensionlessparameters: modulus ratio, depth-to-width ratio and inner-to-outer diameter ratio were determined.Verification of the nominal flexibility ratio was implemented by using three-dimensional dynamic timehistory analyses. The effects of dimensionless parameters (the depth-to-width ratio and the inner-to-outerdiameter ratio) on the shaft response characteristics and the internal forces distribution pattern were carriedout through sensitivity analyses. Results show that the internal forces distribution pattern and deformationmodes of the shafts are determined by the depth-to-width ratio rather than inner-to-outer diameter ratio. Themagnitude of the internal forces are affected by the inner-to-outer diameter ratio with the same shaft'sdepth-to-width ratio and surrounding soil conditions.

82. Shaking table tests on discrepant responses of shaft-tunnel junction in soft soil under transverseexcitations(Published in Soil Dynamics and Earthquake Engineering, 2019, 120: 345-359.)

Shaking table tests on discrepant responses of shaft-tunnel junction in soft soilunder transverse excitations

ZHANG Jinghua, YUAN Yong* and YU Haitao**

ABSTRACT: Due to the special configurations of the shaft-tunnel junction, discrepant responses of theshaft and the tunnel will arise when earthquakes strike. This paper presents shaking table tests addressingthis discrepancy and its influence on the structures. The model system is designed to reproduce the relativestiffness and the relative mass of the prototype system. Two site-specific synthetic earthquake motions areadopted as seismic excitations along the transverse direction of the tunnel model. The discrepant responsesare revealed by the shaft's and the tunnel's acceleration responses. The extent of discrepancy is quantified bycorrelation coefficients, and its influence on structural performance is evaluated. Consequently, thelongitudinal circumferential-joint extensions and the transverse dynamic strains are raised at the shaft-tunneljunction. While the raised strains are relatively small, the longitudinal circumferential-joint extensions posea threat to structural safety. A simplified model based on the solution for Euler-Bernoulli beam on Winklerfoundations is put forward to establish the relation of circumferential-joint extensions and shaft-tunnelrelative displacements. Validation of the proposed model is conducted by comparison of test results andanalytical results.


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83. General Winkler model for kinematic responses of shafts in linear soil(Published in International Journal of Computational Methods, 2019, 1940004:1-16.)

General Winkler model for kinematic responses of shafts in linear soilZHANG Bu and CHEN Zhiyi*

ABSTRACT: A simplified model for calculating the seismic responses of the shaft is proposed in thispaper. Based on the theory of Winkler elastic foundation beam, the urban shaft is simplified as a verticalbeam. The horizontal soil reaction and vertical shear tractions between the shaft circumference and thesurrounding soils are considered through horizontal springs and rotating springs on the sidewall of the shaft.The translation and rocking motion of the shaft are considered through horizontal springs and rotatingsprings at the bottom of the shaft. Then, the dynamic analysis model of the shafts under seismic motion isestablished, and the control equation of the dynamic response of the shaft in frequency domain is deduced.The analytical solution of the steady state response of the shaft is obtained. Considering the randomness ofthe earthquake motion, this method can get the shaft kinematic responses under different ground motionsefficiently in conceptual design process.

84. Experimental studies on the gas temperature and smoke back-layering length of fires in ashallow urban road tunnel with large cross-sectional vertical shafts(Published in Tunnelling and Underground Space Technology, 2019, 83: 565-576)

Experimental studies on the gas temperature and smoke back-layering length of firesin a shallow urban road tunnel with large cross-sectional vertical shafts

GUO Qinghua, ZHU Hehua, YAN Zhiguo*, ZHANG Yao, ZHANG Yinping and HUANG Tianrong

ABSTRACT: A reduced-scale (1:10) tunnel with four vertical shafts is constructed to investigate the firesmoke propagation in a natural ventilation tunnel equipped with large cross-sectional ceiling openings. Aseries of fire tests are performed to explore the impact of fire HRR (Heat Release Rate), shaft height andshaft interval on the gas temperature and smoke back-layering length. It is observed that the smoke cannot fillup the entire cross-section of the shaft, but just propagates adhering to the shaft sidewalls and then spills outof the tunnel. This flow mode of hot smoke in the large cross-sectional shaft is significantly different from thegeneral plug-holing phenomenon, especially for the fresh air entrainment. In such case the fresh air isentrained just along the shaft sidewalls rather than exhausted directly from the lower part of the tunnel.Moreover, experimental results indicate that the dimensionless ceiling gas temperature on the upstream sideof the shaft appears to be independent on the shaft height, while the temperature decay rate on thedownstream side increases with the shaft height. Additionally, the smoke back-layering length generallyincreases with the fire-shaft interval when the shaft height is lower than 0.65 m, while it levels off initiallyand then increases again when the shaft height is higher than 0.65 m. Experimental testing in this papercontributes to understanding of the smoke movement in the naturally ventilated tunnel with largecross-sectional vertical shafts.


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85. Shaking table tests on the intersection of cross passage and twin tunnels(Published in Soil Dynamics and Earthquake Engineering, 2019, 124: 136-150.)

Shaking table tests on the intersection of cross passage and twin tunnelsZHANG Jinghua, YUAN Yong*, BAO Zhen, YU Haitao** and BILOTTA Emilio

ABSTRACT: The abrupt structural change at the intersection of cross passage and twin tunnels is apotential risk when earthquakes strike. This paper addresses the seismic responses of the cross-passageintersection by shaking table tests. Test data from six cases are presented, where white noise and syntheticearthquake motions are adopted. Discrepant responses between the cross passage and the twin tunnels aredescribed by acceleration data. The extent of discrepancy is quantified statistically. Influence of thisdiscrepancy is evaluated in two directions: dynamic strains of the linings in the transverse direction andcircumferential-joint extensions in the longitudinal direction. Since the earthquake-induced dynamic strainsare relatively small, they are considered as an insignificant factor. However, there are considerablecircumferential-joint extensions near the cross passage. Two simplified models are proposed to estimate thejoint extensions in a pseudo-static way. Each model is corresponding to a unique pattern of longitudinaldeformation caused by the discrepant responses of the intersection. Test results are compared with analyticalresults.

86. Development of a novel bio-inspired cement-based composite material to improve the fireresistance of engineering structures(Published in Construction and Building Materials, 2019, 225, 99-111)

Development of a novel bio-inspired cement-based composite material toimprove the fire resistance of engineering structures

ZHANG Tong, ZHANG Yao, XIAO Ziqi, YANG Zhenglong, Zhu Hehua,J Woody Ju and YAN Zhiguo*

ABSTRACT: The mechanical properties of concrete can degrade significantly under high temperature,posing a threat to the safety of structures. In this work, a novel bio-inspired cement-based composite materialthat can improve the fire resistance of engineering structures is put forward. This bio-inspired cementitioussystem, which functions in a manner similar to that of sweat glands and skin in the human body, consists ofAPP-PER-EN composite, synthetic reinforcing fibers, and concrete binder. The APP-PER-EN composite ismainly composed of ammonium polyphosphate, pentaerythritol, and melamine, with low-densitypolyethylene as the base material, which is prepared by melt compounding in a twin-screw extruder followedby grain cutting molding technique. At the micro level, multiple analysis methods are used, including X-raydiffraction, Fourier transform infrared ray, thermo-gravimetric analysis, differential scanning calorimeter, andscanning electron microscopy, to characterize the thermal and flame retardant behavior of this novelcomposite. At the macro level, the one-side heating tests indicate that the thermally triggered fire-resistantsystem can exhibit significant thermal insulation effect through melting, connecting, foaming, andoverflowing. Therefore, the novel composite system is expected to exhibit a promising prospect in the fireresistance of engineering structures.


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87. An equivalent elastoplastic damage model based on micromechanics for hybrid fiber-reinforcedcomposites under uniaxial tension(Published in International Journal of Damage Mechanics, 2019, 1: 79-117)

An equivalent elastoplastic damage model based on micromechanics for hybridfiber-reinforced composites under uniaxial tension

YAN Zhiguo, ZHANG Yao*, J Woody Ju, CHEN Qing and ZHU Hehua

ABSTRACT: A micromechanics-based equivalent elastoplastic damage model for both notch-sensitive andmultiple cracking hybrid fiber reinforced composite is proposed in this study. In this model, the elasticmodulus, first cracking strength, and ultimate strength are estimated based on micromechanics. To quantifystrain after matrix cracks, a novel characteristic length is defined based on the damage mechanics. The effectsof the fiber length, diameter and modulus, and interfacial bond stress on the characteristic length of hybridfiber reinforced composite are presented. In order to avoid the difficulty of determining the traditionaldamage and plastic potential function, this model is developed from the behavior of single fiber at mesolevelto the response of hybrid fiber reinforced composite at macrolevel. Then the calculated results are verifiedwith several published experimental results of fiber reinforced composites and hybrid fiber reinforcedcomposite, including notch-sensitive cracking fiber reinforced composite, multiple cracking fiber reinforcedcomposite, and multiple cracking hybrid fiber reinforced composite reinforced with two types of fibers (steelfiber and polyethylene fiber). The results indicate that enhancement of the tensile performance can beachieved more effectively by improving the polyethylene fiber-like fiber than steel fiber-like fiber.

88. A novel multi-scale model for predicting the thermal damage of hybrid fiber-reinforced concrete(Published in International Journal of Damage Mechanics, 2019)

A novel multi-scale model for predicting the thermal damage of hybridfiber-reinforced concrete

ZHANG Yao*, J Woody Ju, ZHU Hehua and YAN Zhiguo

ABSTRACT: A multi-scale micromechanical model is proposed to predict the damage degree of hybridfiber-reinforced concrete under or after high temperatures. The thermal degradation of hybrid fiber-reinforcedconcrete is generally composed of the damage of the cement paste caused by thermal decomposition andthermal incompatibility, the deterioration of aggregates and fibers, and the interfacial damage betweenaggregates and the matrix. In this multi-scale model, four levels of hybrid fiber-reinforced concrete structuresare considered when the thermal damage degree is derived; namely, the equivalent calcium silicate hydrate(C–S–H) product level, the cement paste level, the concrete level, and the hybrid fiber-reinforced concretelevel. At the cement paste level, thermal decompositions of C–S–H product and calcium hydroxide are takeninto account. In addition, a dimensionless parameter of the crack density is introduced to represent thethermal cracking of the matrix. At the concrete level, the interfacial damage of aggregates is simulated by aspring–interface model, in which the interfacial parameters are assumed to be functions of temperature.Comparisons between previously published experimental data and predictions and discussions illustrate thefeasibility of the proposed multi-scale model in predicting thermal damage of concrete and hybridfiber-reinforced concrete.


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89. Analytical solution for dynamic responses of the vertical shaft in a shaft-tunnel junction undertransverse loads(Published in Soil Dynamics and Earthquake Engineering, 2019, 126: 105779.)

Analytical solution for dynamic responses of the vertical shaft in a shaft-tunnel junctionunder transverse loads

ZHANG Jinghua, YUAN Yong*, BILOTTA Emilio**, ZHANG Bu and YU Haitao.

ABSTRACT: This paper proposes an analytical solution for dynamic responses of the vertical shaft in ashaft-tunnel junction under transverse loads. The assumption is that the shaft could be regarded as a rigidbody under certain circumstances. Based on that premise, equations originally developed for rigid caissonsare incorporated with terms of shaft-tunnel and soil-tunnel interactions. Two specific dynamic scenarios areconsidered. The first one is when the shaft is subject to transverse dynamic loads above the ground surface.The second one is when the shaft-tunnel junction is under transverse seismic excitations. Validity of theproposed solution is examined in both scenarios by finite element method. Then, the proposed solution isused to evaluate influence of the tunnel. In the first scenario, the tunnel has a major influence on dynamicresponses of the shaft. Displacements of the shaft are likely to be reduced because the tunnel adds to thestiffness matrix. Yet, in the second scenario, influence of the tunnel is minor enough to be neglected.Seismic responses of the shaft are approximately the same with or without the tunnel.

90. A stochastic micromechanical framework for hybrid fiber reinforced concrete(Published in Cement and Concrete Composites, 2019, 102: 39-54)

A stochastic micromechanical framework for hybrid fiber reinforced concreteJIANG Zhengwu, YANG Xiaojie*, YAN Zhiguo*, CHEN Qing*, ZHU Hehua,

WANG Yaqiong, J Woody Ju, FAN Zhihong and Li Haoxin

ABSTRACT: A stochastic micromechanical framework is presented to predict the probabilistic behavior ofthe hybrid fiber reinforced concrete (HFRC). The proposed framework consists of the stochastic descriptionsfor the material's microstructures, deterministic micromechanical model for HFRC and maximum entropybased stochastic simulation program. The HFRC is represented as multiphase composite composed of theaggregate, the interfacial transition zone (ITZ), the bulk cement paste and different types of fibers.Multi-level homogenization schemes are presented to predict the material's effective properties, where theeffects of aggregates, ITZs and multi-types of fibers are quantitatively calculated. By modeling the volumefractions and properties of constituents as stochastic, we extend the deterministic framework to stochastic toincorporate the inherent randomness of effective properties among different specimens. Numerical examplesincluding limited experimental validations, comparisons with existing micromechanical models, commonlyused probability density functions and the direct Monte Carlo simulations indicate that the proposed modelsprovide an accurate and computationally efficient framework in characterizing the material's effectiveproperties. Finally, the effects of different fibers and ITZs on the materials' macroscopic probabilisticbehaviors are investigated based on our proposed stochastic micromechanical framework.


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91. Analytical solution for longitudinal bending stiffness of shield tunnels(Published in Tunnelling and Underground Space Technology, 2019, 83: 27-34.)

Analytical solution for longitudinal bending stiffness of shield tunnelsYU Haitao, CAI Chuang, BOBET Antonio, ZHAO Xu*, YUAN Yong

ABSTRACT: The longitudinal bending stiffness of tunnels is one of the most important parameters for thestructural design of the tunnel longitudinal deformations during seismic loading. The aim of the paper is toderive an analytical solution for the longitudinal bending stiffness of a segmental liner, typically used ontunnels built with a shield. For the derivation, it is assumed that the tunnel liner includes bolts, segments andrubber gaskets. All the elements are considered as linear elastic. The bolts are assumed to work only intension and the rubber gaskets are assumed to work only in compression. The deformation of any tunnelcross section complies with the assumption that normals to the neutral axis remain normal and thus theneutral axis does not change along the tunnel during deflection. Based on these assumptions, a longitudinalequivalent model for shield tunnels is developed and the governing equations are obtained. A closed-formanalytical solution for the longitudinal bending stiffness is developed and verified by providing comparisonsbetween its results and those from the Finite Element program ABAQUS. A parametric analysis, using thenew analytical solution, is included to investigate the influence of key parameters such as the thickness of therubber gaskets, the ratio of the liner thickness to the internal tunnel diameter, and the transverse bendingstiffness of the tunnel cross section on the longitudinal bending stiffness of the tunnel.

92. Experimental testing on ductile-iron joint panels for high-stiffness segmental joints ofdeep-buried drainage shield tunnels(Published in Tunnelling and Underground Space Technology, 2019, 87: 145-159)

Experimental testing on ductile-iron joint panels for high-stiffness segmental joints ofdeep-buried drainage shield tunnels

ZHOU Long, ZHU Hehua, YAN Zhi-guo*, SHEN Yi, MENG Han, GUAN Linxing and WEN Zhu-yin

ABSTRACT: Because of the large earth pressure and high inner water pressure, high-stiffness segmentaljoints with ductile-iron joint panels (DIJPs) are needed to improve the bearing capacity of segmental jointsfor deep-buried drainage shield tunnels. Full-scale tensile experiments on the performance of DIJPs withdifferent structural styles, in terms of deformation characteristic, anchorage property, and failure mode, werecarried out to evaluate the applicability of DIJPs for deep-buried drainage shield tunnels. The test resultsshow that bending deflection appears in DIJPs if the flexural rigidity of DIJPs is insufficient, which willcause bending-tensile failure for the DIJP anchor bars. The failure position is in the weak interface: the screwthread position of the anchor bars, which is the connection position between the anchor bars and DIJPs;connecting the anchor bars with the main reinforcing bars by stirrups or filling the hand hole can restrain thebending deflection of the DIJP and improve the bearing capacity of the anchor bars. When the anchor bars areconnected with the main reinforcing bars, the deformation of the DIJP decreases by 5.6%, and the bearingcapacity of the anchor bars increases by 31.1%. Considering the failure modes of the specimens, it is believedthat increasing the flexural rigidity of the DIJP and improving the connection performance between the DIJPand anchor bars can improve the behavior of the DIJP and anchor bars.


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93. Experimental investigation of pedestrian evacuation using an extra-long steep-slope evacuationpath in a high altitude tunnel fire(Published in Sustainable Cities and Society, 2019, 46: 101423)

Experimental investigation of pedestrian evacuation using an extra-long steep-slopeevacuation path in a high altitude tunnel fire

ZHANG Yuxin, YAN Zhiguo*, ZHU Hehua, SHEN Yi, GUO Qinghua and GUO Qingchao

ABSTRACT: This paper presents outcomes of a field experiment involving a random sample of pedestriansevacuating from a newly-constructed long tunnel at high altitude through an extra-long evacuation path witha steep grade. Adverse survival conditions include high altitude, reduced oxygen, long distance, and the steepslope of the evacuation path. Research methods include field experiments, questionnaires and interviews.Response time, route choice, movement time, speed change, and reaction to technical installations wererecorded and discussed both in the tunnel and the evacuation path. The influence of adverse survivalconditions was analyzed and compared with general evacuation cases. The human factors, includingpedestrians’ genders, ages and emotional states were also investigated. The results of this study have resultedin guidance on evacuation planning and procedures and suggestions regarding technical installations in thetunnel, such as way-finding signs, loudspeakers, continuous lights and handrails.

94. A novel damage model based on micromechanics for hybrid fiber reinforced cementitiouscomposites under uniaxial compression(Published in International Journal of Damage Mechanics, 2019, 28(07): 1095-1132)

A novel damage model based on micromechanics for hybrid fiber reinforced cementitiouscomposites under uniaxial compression

ZHANG Yao, J Woody Ju, ZHU Hehua, CHEN Qing, GUO Qinghua and YAN Zhiguo*

ABSTRACT: A novel damage model based on micromechanics is proposed for hybrid fiber reinforcedcementitious composites under uniaxial compression. To account for the contribution of microcracks on itsmacrocompliance under compression, hybrid fiber reinforced cementitious composite is consideredequivalent to the microcrack-weakened solid, whose overall compliance consists of the compliance of thematrix and the additional compliance by sliding, propagating and kinking cracks. The bridging effects ofhybrid fibers on restraining crack growth are simplified based on the reality that the average slidingdisplacement of microcracks is much less than the length of reinforcing fibers. The evolutional domains ofmicrocrack growth under loads where the microcracks are sliding, propagating and kinking are discussed indetail. In addition, the weakening effects of fibers upon compressive behavior are captured by introducingtwo functions, which consider the influences of fiber geometrical parameters, the microcrack density and thedistance between two nearest microcracks with the same oriented angle. Simulation results by ourevolutionary damage model render reasonable agreements with available experimental data of fiberreinforced cementitious composites and hybrid fiber reinforced cementitious composites with various fibercontents. The new micromechanical damage model would be beneficial to elucidating the strengthening andweakening mechanisms of hybrid fiber reinforcement.


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95. Experimental study of pullout capacity of plate anchors shallowly embedded in hydrate bearingsediments (Published in Ocean Engineering, 2019, 173: 548-555)

Experimental study of pullout capacity of plate anchors shallowly embeddedin hydrate bearing sediments

LIU Fang, SUN Haoyu, JUNG Jongwon, ZHANG Xuhui and JU Xin

ABSTRACT: Plate anchors are commonly used in mooring systems of offshore facilities for gas and oilproduction in deep and ultra-deep water. They may encounter hydrate-bearing sediments widespread inmarine continental margins. The pullout capacity of square anchors embedded shallowly in a hydrate-bearingsand is investigated with small-scale model tests using tetrahydrofuran (THF) hydrate as the substitute of gashydrate. The results show that the pullout capacity of the anchors increases with the increase of the anchorwidth and the burial depth. The pullout capacity of the anchors can be estimated by a dimensionless breakoutfactor. This factor increases with the increase of the burial depth ratio (defined as the ratio of the burial depthto the width of a plate anchor), exhibiting a trend similar to that obtained numerically and experimentallyfrom plate anchors shallowly-embedded in undrained clays. Hydrate dissociation brings detrimental effectson the pullout capacity of the anchors. The pullout capacity of the anchors drops to 0.3% of the initial valueafter the hydrates dissociate. This pronounced reduction highlights the need for further investigation on theeffect of oceanic hydrate dissociation on engineering performance of offshore facilities as a result of naturalor anthropologic perturbation.

96. Seismic performance of framed underground structures with self-centering energy-dissipationcolumn base(Published in Advances in Structural Engineering, 2019, 22: 2809-2822.)

Seismic performance of framed underground structures with self-centeringenergy-dissipation column baseCHEN Zhiyi* and ZHOU Yu

ABSTRACT: For the development of underground structures toward large-scale, long-span, and complexstructural styles, comprehensive seismic mitigation and controlling measures that consider reducing internalforces together with controlling lateral structural deformation and upgrading energy consumption aresignificant for improving seismic performance and enhancing resilience of underground structure. For thispurpose, a self-centering energy-dissipation column base, which originated from the concept of earthquakeresilient structures in aboveground space, is proposed for the framed underground structures in this study. Toverify the effectiveness of self-centering energy-dissipation column base, three-dimensional time historyanalyses are conducted on a single-story double-span subway station. The analysis results show that theself-centering energy-dissipation column base effectively decreases the internal forces of central column andthe peak and residual values of story drift and column drift are also minimized about 4%–5%. Meanwhile, itis found that a cyclic opening–closing exists at the column base during an earthquake and the uplift ofcolumn returns to zero at the end of the earthquake. It means the self-centering effect of the column base isachieved as expected. Moreover, replaceable energy-dissipating devices provide supplementary energydissipation to relieve the development of structural plasticity and the uplift behavior of column base avoidsthe occurrence of plastic hinge. As a result, the structural damages are effectively reduced after theearthquake.


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List of Other Recent Publications (SCI, EI index)1. JIANG Mingjing, LIANG Huali, LIAO Youbin, LIU Sun and WANG Huaning. Distinct Element Method Analysis of the

Failure Evolution of Rock Slope with Different Types of Joints. Journal of Tongji University (Natural Science), 2019,47(2): 167-174. (in Chinese, EI indexed)

2. LI Jie and REN Xiaodan. Chairmen report of the third international conference on damage mechanics, ICDM3Shanghai, 4-6 July 2018 (Published in International Journal Of Damage Mechanics,2019, 28(5), 643-646)

3. RUI Zhenmei and CHEN Jianbing. Dimension reduction of FPK equation for velocity response analysis of structuressubjected to additive nonstationary excitations. Chinese Journal of Theoretical and Applied Mechanics, 2019, 51(3):922-931

4. SONG Yupeng, CHEN Jianbing and PENG Yong-bo. Simulation of nonhomogeneous fluctuating wind field inone-dimensional space by evolutionary wavenumber-frequency joint power spectrum. Engineering Mechanics, 2019,36(2): 205-214

5. CHEN Jun, WANG Jinping and James M. W. Brownjohn. Power spectral-density model for pedestrian walking load,Journal of Structural Engineering, ASCE, 2019, 145(2): 04018239

6. WANG Haoqi, CHEN Jun and Tomonori Nagayama. Parameter identification of spring-mass-damper model forbouncing people, Journal of Sound and Vibration, 2019, 456:13-29

7. SHEN Jiaxu, REN Xiaodan, ZHANG Yongqun and CHEN Jun. Nonlinear dynamic analysis of frame-core buildingunder seismic sequential ground motions by a supercomputer, Soil Dynamics and Earthquake Engineering, 2019,124:13-29

8. CHEN Jun, TAN Huan, Katrien Van Nimmen and Peter Van den Broeck. Data-driven synchronization analysis of abouncing crowd, Shock and Vibration, Volume 2019, Article ID: 8528763

9. LI Suzhen, WEI Chen, and PENG Xinghua. Safety Monitoring of Buried Pipeline with Socket Joints Subjected toGround Deformation Using MEMS Inclinometers, Journal of Pipeline Systems Engineering and Practice, 2019, 10(3),04019008

10. CHEN Shu, LI Suzhen and Huang Dongdong. Monitoring of soil temperature field due to leakage of buried thermalpipeline using distributed fiber optic sensor, Chinese Journal of Scientific Instrument, 2019, 40(3):138-145

11. ZHAO Wuchao and QIAN Jiang. Study on local response characteristics of RC beams under impact loading. Journalof Hunan University (Natural Sciences), 2019, 46(03): 25-32. (in Chinese, EI indexed)

12. ZHAO Wuchao and QIAN Jiang. Performance of reinforced concrete pier columns subjected to lateral impact.Chinese Journal of Engineering, 2019, 41(03): 408-415. (in Chinese, EI indexed)

13. CHEN Yun, JIANG Huanjun, LIU Tao, WAN Zhiwei and LU Zheng. Study on the seismic behavior of graded yieldingmetal dampers. Gongcheng Lixue/Engineering Mechanics, 2019, 36(3): 53-62. (in Chinese, EI indexed)

14. ZHOU Ying and GU Anqi. Displacement-based seismic design of self-centering shear walls under four-level seismicfortifications. Journal of Building Structures, 2019, 40(3): 118-126. (in Chinese, EI indexed)

15. ZHOU Ying and CHEN Peng. Investigation on a vertical isolation system with quasi-zero stiffness for buildingstructures. Journal of Building Structures, 2019, 40(4): 143-150. (in Chinese, EI indexed)

16. ZHOU Ying, WU Hao and GU Anqi. Earthquake engineering: from earthquake resistance, energy dissipation, andisolation to resilience. Engineering Mechanics, 2019. (in Chinese, EI indexed)

17. WANG Liangkun, SHI Weixing, ZHOU Ying and ZHANG Yiqing. Study on semi-active eddy current pendulum tunedmass damper under earthquake excitations. Journal of Building Structures, 2019, 40(5): 184-190. (in Chinese, EIindexed)

18. JIANG Huanjun and LI Yinghui. Deformation limit analysis of steel reinforced concrete coupling beams. Proceedingsof the fib Symposium 2019: Concrete-Innovations in Materials, Design and Structures, 2019: 849-856. (in English, EIindexed)

19. ZHAO Bin, WANG Yan, LU Xilin and SHI Chuanxia. Research on seismic behaviour of full precast concrete wallsassembled by new horizontal joint. Proceedings of the fib Symposium 2019: Concrete-Innovations in Materials,Design and Structures, 2019, p1251-1258. (in English, EI indexed)

20. LI Xin, ZHAO Bin and LU Xilin. Contrastive analysis on seismic performance between cast-in-situ and precast RCframe structure. Proceedings of the fib Symposium 2019: Concrete-Innovations in Materials, Design and Structures,2019, p2286-2293. (in English, EI indexed)

21. LU Xilin, ZHANG Ying, LI Xin and ZHANG Hongmei. Modelling and parametric study of steel fiber reinforced highstrength concrete composite shear walls. Proceedings of the fib Symposium 2019: Concrete-Innovations in Materials,Design and Structures, 2019, p605-612. (in English, EI indexed)

22. CHEN Yun, CHEN Chao, JIANG Huanjun, WAN Zhiwei and LIU Tao. Experiment analysis of mechanical properties


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of o-shaped steel plates and high damping viscoelastic composite energy dissipators. Engineering Mechanics, 2019,36(1): 119-128. (in Chinese, EI indexed)

23. CHEN Yun, JIANG Huanjun, LIU Tao, WAN Zhiwei and LU Zheng. Study on the seismic behavior of graded yieldingmetal dampers. Engineering Mechanics, 2019, 36(3): 53-62. (in Chinese, EI indexed)

24. LIU Xiaojuan and JIANG Huanjun. Study on time-dependent seismic performance of reinforced concretemoment-resisting frame structures. Journal of Building Structures, 2019, 40(3): 134-141. (in Chinese, EI indexed)

25. ZHAO Huiling, YUAN Yong, YE Zhiming, YU Haitao and ZHANG Zhiming. Response characteristics of an atriumsubway station subjected to bidirectional ground shaking. Soil Dynamics and Earthquake Engineering, 2019, 125:105737. (SCI)

26. ZHAO Huiling, YU Haitao, YUAN Yong, LI Pan and CHEN Juntao. Cyclic loading behavior of a repaired subwaystation after fire exposure. Tunnelling and Underground Space Technology, 2019, 84: 210-217. (SCI)

27. LU Limin, QIU Junnan, YUAN Yong, TAO Jin, YU Haitao, WANG Hui and Mang Herbert.Large-scale test as the basisof investigating the fire-resistance of underground RC substructures. Engineering Structures, 2019, 178: 12-23. (SCI)

28. YU Haitao, XIAO Wenhao, ZHAO Xu, YUAN Yong, CHAI Rui and LIU Hongzhou. Compression performance offlexible joints in immersed tunnels [J]. China Journal of Highway and Transport, 2019, 32(5): 115-122, 180. (EI)

29. YU Haitao, ZHANG Zhengwei, LI Pan, HE Weiguo and ZHAO Xu. Analytical solution for longitudinal seismicresponses of long tunnels crossing soil-rock stratum. Chinese Journal of Geotechnical Engineering, 2019, 41(7):1244-1250. (EI)

30. YAN Zhiguo, ZHOU Long, ZHU Hehua and SHEN Yi. Experimental Study on Mechanical Properties of Ductile-IronJoint Panels for Segmental Joints in Deep-Buried Drainage Shield Tunnels. Journal of Tongji University, 2019, 47(03):331-338. (in Chinese, EI indexed)

31. DU Yong, SUN Yakai and LI Guoqiang. Mechanical properties of high tensile steel cables at elevated temperature.Engineering Mechanics, 2019, 36(4): 231-238. (in Chinese, EI indexed)

32. LYU Yifan, LI Guoqiang and WANG Yanbo. Experimental research on the strength of bolted connections of highstrength steel with grade over 500 MPa. Engineering Mechanics, 2019, 36(5): 200-207,215. (in Chinese, EI indexed)

33. WANG Lingling, SUN Yi, FAN Guangming and LI Guoqiang. Effect of Heating Regime on Thermal InsulationProperties of Intumescent Coating. Journal of Building Materials, 2019, 22(1): 101-107. (in Chinese, EI indexed)

34. SUN Limin, ZHANG Wei and Nagarajaiah Satish. Bridge Real-Time Damage Identification Method Using Inclinationand Strain Measurements in the Presence of Temperature Variation, Journal of Bridge Engineering, Vol.24, No.2,Feb. 2019; (SCI)

35. XIE Wen and SUN Limin. Experimental and numerical verification on effects of inelastic tower links on transverseseismic response of tower of bridge full model, Engineering Structures, Vol.182, P344-362 , Mar. 2019; (SCI)

36. ZHOU Yi and SUN Limin. Insights into temperature effects on structural deformation of a cable-stayed brdge basedon structural health monitoring, Structural Health Monitoring, Vol.18, No.3, P778-791, May. 2019；(SCI)

37. SUN Limin and XIE Wen. Experimental assessment of soil-structure interaction effects on a super long-spancable-stayed-bridge with pile group foundations, Bulletin of Earthquake Engineering, Vol.17, No.6, P3169-3196, Jun.2019；(SCI)

38. ZHOU Yi and SUN Limin. A comprehensive study of the thermal response of a long-span cable-stayed bridge: frommonitoring phenomena to underlying mechanisms, Mechanical Systems and Signal Processing, Vol.124,P330-348,Jun. 2019；(SCI)

39. NI Yanchun, ZHANG Qiwei and LIU Jianfeng. Dynamic Property Evaluation of a Long-Span Cable-Stayed Bridge(Sutong Bridge) by a Bayesian Method. International Journal of Structural Stability and Dynamics. 2019, 19(1):1940010 (SCI).

State Key Laboratory of Disaster Reduction in Civil EngineeringAdministration office:

Bridge Hall, Tongji University, 1239 Si Ping Road, ShanghaiPost Code: 200092Tel: +86-21-65982397 E-mail: sldrce @ tongji.edu.cn

Documents

Contents - sldrce.tongji.edu.cn · 2019 National Conference on Wind-induced Vibration, Monitoring and Control in Shantou on Mar.22-24th,2019.ProfZHULedongwasinvited to give a keynote