Development and validation of side-impact crash and sled testing finite-element models

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<ul><li><p>This article was downloaded by: [University of California, San Francisco]On: 19 November 2014, At: 07:54Publisher: Taylor &amp; FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registeredoffice: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK</p><p>Vehicle System Dynamics: InternationalJournal of Vehicle Mechanics andMobilityPublication details, including instructions for authors andsubscription information:http://www.tandfonline.com/loi/nvsd20</p><p>Development and validation of side-impact crash and sled testing finite-element modelsTso-Liang Teng a , Kuan-Chun Chang a &amp; Chien-Hsun Wu ba Department of Mechanical and Automation Engineering , Da-YehUniversity , Changhua, Taiwan, ROCb Automotive Research and Testing Center , Changhua County ,Taiwan, ROCPublished online: 30 Aug 2007.</p><p>To cite this article: Tso-Liang Teng , Kuan-Chun Chang &amp; Chien-Hsun Wu (2007) Developmentand validation of side-impact crash and sled testing finite-element models, Vehicle SystemDynamics: International Journal of Vehicle Mechanics and Mobility, 45:10, 925-937, DOI:10.1080/00423110701560068</p><p>To link to this article: http://dx.doi.org/10.1080/00423110701560068</p><p>PLEASE SCROLL DOWN FOR ARTICLE</p><p>Taylor &amp; Francis makes every effort to ensure the accuracy of all the information (theContent) contained in the publications on our platform. 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Terms &amp;</p><p>http://www.tandfonline.com/loi/nvsd20http://www.tandfonline.com/action/showCitFormats?doi=10.1080/00423110701560068http://dx.doi.org/10.1080/00423110701560068</p></li><li><p>Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Uni</p><p>vers</p><p>ity o</p><p>f C</p><p>alif</p><p>orni</p><p>a, S</p><p>an F</p><p>ranc</p><p>isco</p><p>] at</p><p> 07:</p><p>54 1</p><p>9 N</p><p>ovem</p><p>ber </p><p>2014</p><p>http://www.tandfonline.com/page/terms-and-conditionshttp://www.tandfonline.com/page/terms-and-conditions</p></li><li><p>Vehicle System DynamicsVol. 45, No. 10, October 2007, 925937</p><p>Development and validation of side-impact crash and sledtesting finite-element models</p><p>TSO-LIANG TENG*, KUAN-CHUN CHANG and CHIEN-HSUN WU</p><p>Department of Mechanical and Automation Engineering, Da-Yeh University, Changhua, Taiwan, ROCAutomotive Research and Testing Center, Changhua County, Taiwan, ROC</p><p>Side-impact collisions are the second leading cause of death and injury in the traffic accidents afterfrontal crashes. Side-impact airbags, side door bars and other protection techniques have been devel-oped to provide occupant protection. To confirm the effectiveness of protection equipment installed invehicles, studying the degree of impact is fundamental to understand the effect of automobile collisionson the human body. Therefore, the dynamic response of the human body to traffic accidents shouldbe analyzed to reduce the level of occupant injuries. Generally, the experimental method is complexand expensive. Recently, numerical crash simulations have provided a valuable tool for automotiveengineers. This work presents full-scale and sled side-impact test finite-element (FE) models basedon the Federal Motor Vehicle Safety Standard No. 214 that simulate a side-impact accident. Thecrash simulations utilized the LS-DYNA finite-element code. The human bodys dynamic response tocrashes is discussed herein. Additionally, occupant injuries were measured. To verify the accuracy ofthe proposed crash test and sled test FE models, simulation results are compared with those obtainedfrom experimental tests. The comparison results indicate that the proposed crash test and sled test FEmodels have considerable potential for assessing a vehicles crash safety performance and assistingfuture development of safety technologies.</p><p>Keywords: Side impact; Full-scale crash test; Sled test; Simulation; Injury</p><p>1. Introduction</p><p>Traffic accidents claim 10,000 lives annually. Vehicle safety became a common concern ofmanufacturers and consumers. Accident statistics [1] indicate that injury and fatality rates infrontal collisions exceed those from side collisions and rear-end impacts. Manufacturers havemade significant improvements in protecting occupants during head-on collisions. Notably,side-impact collisions are the second leading cause of death and injury in the traffic accidentsafter frontal crashes. Unlike a frontal collision, side-impact collisions are unique; that is,the space between an occupant and the side of the vehicle is minimal. Hence, the occupanthas very little protection when a vehicle is struck on its side. Side-impact airbags, side doorbars and other protection techniques have been developed to occupant protection. Assessingthe effectiveness of protective equipment is crucial during the design stage. Discussing theinteraction between vehicle occupants and passive safety devices is essential when developing</p><p>*Corresponding author. Email: tlteng@mail.dyu.edu.tw</p><p>Vehicle System DynamicsISSN 0042-3114 print/ISSN 1744-5159 online 2007 Taylor &amp; Francis</p><p>http://www.tandf.co.uk/journalsDOI: 10.1080/00423110701560068</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Uni</p><p>vers</p><p>ity o</p><p>f C</p><p>alif</p><p>orni</p><p>a, S</p><p>an F</p><p>ranc</p><p>isco</p><p>] at</p><p> 07:</p><p>54 1</p><p>9 N</p><p>ovem</p><p>ber </p><p>2014</p></li><li><p>926 T.-L. Teng et al.</p><p>safe and effective protective equipment. Therefore, researching the degree of impact a bodyundergoes during an impact is fundamental to vehicle safety design.</p><p>Analyzing the dynamic response of an occupant during a vehicle collision and confirmingthe effectiveness of vehicle protection equipment requires developing an efficient evaluativeand analytical methodology that can assess the safety aspects of a vehicle. Generally, dynamicresponse of and injury to human bodies in crash tests can be analyzed in two ways: experimen-tal and numerical simulations. The experimental analysis can be further deconstructed intofull-scale crash tests [13] and sled experiments [46]. Crash testing is commonly employedfor examining occupant protection capability of a particular vehicle. Although full-scale crashtests can achieve results that closely resemble an actual accident, this method is complexand expensive. Sled testing is an effective means of evaluating crash safety of vehicle inte-riors. This technique can simulate real crash conditions without destroying vehicle structure.Therefore, the sled system is typically employed to assess the protective capability of safetyequipment during vehicle research and development stages. Recently, advances in computertechnology have allowed applied mathematicians, engineers and scientists to solve previ-ously intractable problems. The crash and sled tests can be performed exactly by computersimulations. As such, computer simulation is an economical and time efficient alternativeto physical testing. Simulation methods for predicting occupant kinematics and calculatinginjury criteria include MADYMO, Pam Crash and LS-DYNA [711]. Advances in numericalsimulation techniques and computer capabilities have made computer testing a powerful toolfor investigating crash safety. Moreover, computer simulation for crashworthiness evaluationhas contributed to shortening the time required to design vehicles.</p><p>To confirm vehicle occupant safety, most countries issue safety standards and regulations towhich vehicles must conform, such as the Federal Motor Vehicle Safety Standards (FMVSS)and the Economic Commission for Europe (ECE) regulations, etc. Safety standards and reg-ulations are typically minimum safety performance standards for motor vehicles and theirrelated equipment. A goal of these standards is to protect the public against unreasonablerisk of crashes that result from design, construction or performance of motor vehicles andagainst unreasonable risk of death or injury during a crash. To meet these regulations anddevelop equipment with enhanced safety, finite-element (FE) modeling in simulations can beused to investigate the dynamic behavior of occupants and injury analysis. This work presentsfull-scale and sled side-impact test FE models based on the FMVSS-214 that simulatea side-impact accident. The crash simulations utilized the LS-DYNA FE code. The humanbodys dynamic response to crashes is discussed herein. Additionally, occupant injuries weremeasured. To verify the accuracy of the proposed crash test and sled test FE models, simula-tion results are compared with those obtained from experimental tests. The comparison resultsindicate that the proposed crash test and sled test FE models have considerable potential forassessing a vehicles crash safety performance and assisting future development of safetytechnologies.</p><p>2. Full-scale crash test</p><p>2.1 Regulation</p><p>Side-impact protection standards have been adopted in both the USA and the Europe. FMVSS-214 (USA) and ECE-R95 (European) dynamic side-impact regulations are quite different,especially with respect to their concerns about occupant injury. In this study, a side-impacttest was performed according to the FMVSS-214 specification.</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Uni</p><p>vers</p><p>ity o</p><p>f C</p><p>alif</p><p>orni</p><p>a, S</p><p>an F</p><p>ranc</p><p>isco</p><p>] at</p><p> 07:</p><p>54 1</p><p>9 N</p><p>ovem</p><p>ber </p><p>2014</p></li><li><p>Development and Validation of Side-Impact Crash and Sled Testing FE Models 927</p><p>Figure 1. The test set-up of FMVSS-214.</p><p>FMVSS-214 specifies performance requirements for protection of occupants in side-impactcrashes. The aim of this standard is to reduce the risk of serious and fatal injury to occupants ofmotor vehicles in side-impact crashes by setting vehicle crashworthiness requirements in termsof accelerations measured on anthropomorphic dummies in test crashes. For the physical test,the procedure was simplified with the struck vehicle stationary and the moving deformablebarrier (MDB) striking the target vehicle. Wheels of the deformable barrier were crabbed atan angle of 27 from the longitudinal direction of the barrier. Figure 1 shows the test set-up. Dummies in vehicle must satisfy the requirements of FMVSS-214 when the stationaryvehicle is impacted by MDB at 54 km/h (33.5 mph). This test was intended to simulate anintersection crash involving two moving vehicles. Dummy injuries to the thorax and pelvicarea were assessed along with vehicle structural damage.</p><p>The thorax and the pelvis are mainly injured by side impact. The US-SID dummy responsemeasurements consisted of the thorax and pelvic accelerations. The FMVSS-214 specificationstipulates that the TTI shall not exceed 85 and 90 g for a passenger car with four side doorsand with two side doors, respectively. And the peak lateral acceleration of the pelvis shall notexceed 130 g for all vehicles.</p><p>2.2 FE models of full-scale crash test</p><p>The FE side-impact test model was conducted according to the FMVSS-214 specification andprocedure. The model is shown in figure 2. The model consisted of three systems combinedinto one FE model: (1) the side-impact vehicle model; (2) the MDB model and (3) the US-SIDmodel. Overall models of side-impact test are validated according to the FMVSS-214. Thevalidations are described in [12].</p><p>In this study, a Ford Taurus model was analyzed in a dynamic side-impact test. The full-vehicle FE model was developed by EASi Engineering for the National Highway Traffic SafetyAdministration (NHTSA). The FE model of the Ford Taurus has 171 parts, representing thevehicle components. The full-vehicle FE model for the side-impact simulation, consistingof 49,453 nodes and 5,327 elements, was used. The MDB, weighing 1,367 kg, is designed</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Uni</p><p>vers</p><p>ity o</p><p>f C</p><p>alif</p><p>orni</p><p>a, S</p><p>an F</p><p>ranc</p><p>isco</p><p>] at</p><p> 07:</p><p>54 1</p><p>9 N</p><p>ovem</p><p>ber </p><p>2014</p></li><li><p>928 T.-L. Teng et al.</p><p>Figure 2. FE model of the full-scale side-impact test: a) front view, b) isometric view.</p><p>to represent an average mid-size vehicle in the US market. The FE model of the MDB wasoriginally developed by NHTSA. The model is composed of seven components, 8,908 nodesand 5,848 elements. The US-SID FE model used in the simulation is based on the Hybrid III50% dummy. The model includes the head, neck, upper spine, lumbar spine, pelvis, upper legs,lower legs, feet, jacket and ribcage. The geometry of the different components of the dummywas obtained from design drawings of the Hybrid III 50% dummy. The model is composedof 69 components, 43,874 nodes and 57,032 elements. The overall mass, and the mass andinertia of each component of the dummy, match those of the Hybrid III 50% dummy.</p><p>3. Side-impact sled test</p><p>3.1 Side-impact sled system</p><p>The proposed side-impact sled systems, such as the BASIS system of TNO automotive(figure 3a) and the M-SIS system of HYGE Inc., were developed to assess vehicle</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Uni</p><p>vers</p><p>ity o</p><p>f C</p><p>alif</p><p>orni</p><p>a, S</p><p>an F</p><p>ranc</p><p>isco</p><p>] at</p><p> 07:</p><p>54 1</p><p>9 N</p><p>ovem</p><p>ber </p><p>2014</p></li><li><p>Development and Validation of Side-Impact Crash and Sled Testing FE Models 929</p><p>manufacturers in developing side-impact safety technology. The sled system simulates aninner door panel to occupant intrusion during a side impact. This tests set-up is appropriatefor the development of airbags and trim panel stiffness. By utilizing a sled test facility and elim-inating the need for test vehicles, this system is a cost effective alternative to full-scale crashtesting. The side-impact sled system was developed to realistically simulate the kinematics ofa full-scale side-impact crash test. This system utilizes the sleds computer-controlled brakingsystem to precisely trace the acceleration and deceleration of the crash vehicle. The BASISsystem is employed in this work as an example to illustrate the components of a sled system[13]. As figure 3b indicates, the test set-up is a frame (1) on which a door (2) is mounted;next to the door is a seat, in which a dummy sits, placed on a smaller sled (3) that runs onlinear rails (4). Both the frame and rails are attached to the inverse crash simulator (ICS) sled.An appropriate pulse for the ICS is based on a full-scale test or computer simulation. Whena pulse is applied, the seat with the instrumented dummy moves along the linear rails towardthe door due to inertia. Similar to its action during a full-scale impact, the dummy hits a side</p><p>Figure 3. BASIS system of TNO automotive [13].</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Uni</p><p>vers</p><p>ity o</p><p>f C</p><p>alif</p><p>orni</p><p>a, S</p><p>an F</p><p>ranc</p><p>isco</p><p>] at</p><p> 07:</p><p>54 1</p><p>9 N</p><p>ov...</p></li></ul>

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