Proceedings of the ASME

11th Biennial Conference on

Engineering Systems

Design and Analysis

-2012 -

VOLUME 1

advanced computational mechanics

advanced simulation-based engineering sciences

virtual and augmented reality

applied solid mechanics and material processing

dynamical systems and control

presented at

ASME 2012 11th BIENNIAL CONFERENCE ON ENGINEERING SYSTEMS DESIGN AND ANALYSIS

JULY 2-A, 2012

NANTES, FRANCE

sponsored byASME

ASME

Three Park Avenue* New York, N.Y. 10016

CONTENTS

ADVANCED COMPUTATIONAL MECHANICS

ESDA2012-82032. 1

Crack Initiation and Propagation as Part of Engineering DesignHans Minnebo, Marc Duflot, and Eric Wyart

ESDA2012-82046 9

Heavy Truck 5th Wheel Modeling Techniques in Finite Element and Their Effect on

Stress Distribution

AH Cinar

ESDA2012-82068 13Verification of a Finite Element Model of an Unmanned Aerial Vehicle Wing Torque Box via

Experimental Modal TestingLevent Unlusoy, Melin Sahin, and Yavuz Yaman

ESDA2012-82247 21

Performance Assessment of Hexahedral Meshing Methods for Design and Mechanical

Analysis of Composite Materials

Lev Podshivalov, Anath Fischer, and Pinhas Z. Bar-Yoseph

ESDA2012-82437 29

Modelling Local Dynamic Pressure Within Inflatable Sports Balls

Henry Hanson, Andy Harland, Chris Holmes, Dan Price, and Tim Lucas

ESDA2012-82489 37First Steps in the Space Separated Representation of Models Defined in Complex Domains

Chady Ghnatios, Amine Ammar, Alain Cimetiere, Aziz Hamdouni, Adrien Leygue, andFrancisco Chinesta

ESDA2012-82637 43

Using Welding Simulation and Ultrasonic Method to Evaluate Residual Stress inStainless Steel Welded Plates

Yashar Javadi, Mohammadreza Hadizadeh Raeisi, Hamed Salimi Pirzaman, andMehdi Ahmadi Najafabadi

ESDA2012-82689 51

Simulation of Noise Attenuation Using One and Two Degree of Freedom HelmholtzResonators in PipelinesMaaz Farooqui and Samir Mekid

ESDA2012-82697 59

Geometry Effects on the Noise Reduction of Helmholtz Resonators

M. Farooqui, A. Alhamoud, A. Aliuddin, and S. Mekid

v

ESDA2012-82246 123

Uncertainty Quantification in Computational Nonlinear ElasticityE. Capiez-Lernout, C. Soize, and M.-P. Mignolet

ESDA2012-82252 133

Optimal Spring Balancing Cylinder Design of an Industrial Robot Using Multi-Disciplinaryand Multi-Objective Optimization

Jakob Westrom, Xiaolong Feng, Hans Andersson, and Stefan Lunderius

ESDA2012-82260 141

A Study on the Dynamic Load Simulation for a Crawler Excavator ConsideringGround Effect

Seongpil Yang, Mooseung Kim, Donghyeon Hwang, and Panyoung Kim

ESDA2012-82281 147

Assessment of Modal Strain Energy Method: Advantages and Limitations

Hasan Koruk and Kenan Y. Sanliturk

ESDA2012-82298 155

Evaluation of Drivers' Attention Level by a Driving Simulator

Riccardo Bartolozzi and Francesco Frendo

ESDA2012-82301 167

A Regression Based Non-Intrusive Method Using Separated Representation for

Uncertainty Quantification

Prashant Rai, Mathilde Chevreuil, Anthony Nouy, and Jayant Sen Gupta

ESDA2012-82304 175

Proper Generalized Decomposition to Solve a 2D Coupled Heat-Diffusion Problem

T. L. Nguyen, M. Beringhier, and J. C. Grandidier

ESDA2012-82331 ,177

A Parallelized Node-Centered Finite Volume Method for Computing Radiative Heat Transfer

on 3D Unstructured Hybrid Grids

Georgios N, Lygidakis and loannis K. Nikolos

ESDA2012-82344 187

Optimization of the Global Static and Dynamic Performance of a Vehicle Body by Means of

Response Surface Models

Pavlina Mihaylova, Alessandro Pratellesi, Niccold Baldanzini, and Marco Pierini

ESDA2012-82389 197

Multiscale Model Reduction for the Solution of Stochastic Partial Differential EquationsWith Localized Sources of Uncertainties

Elias Safatly, Mathilde Chevreuil, andAnthony Nouy

ESDA2012-82407 205

PGD-BEM Applied to the Nonlinear Heat EquationPierre Joyot, Gael Bonithon, Nicolas Verdon, Francisco Chinesta, and Pierre Villon

vii

ESDA2012-82711 ,

67

Handling Localization in Damage Models With the Thick Level Set Approach (TLS)

Nicolas Moes, Paul-Emile Bernard, Claude Stolz, and Nicolas Chevaugeon

ESDA2012-82727 71

Efficiency of Implicit Symplectic Finite-Difference Time-Domain Method for

Near-Field OpticsIkuo Saitoh and Makoto Naruse

ESDA2012-82737 75

Computational Models for Resistance Spot Welding

Pierluigi Mollicone, Martin Muscat, and Matthew Said

ESDA2012-82932 81

Modelling Chemical Processes in Cement Based Materials by Means of Multiphase

Porous Media Mechanics

Francesco Pesavento, Dariusz Gawin, Bernhard A Schrefler, and Marcin Koniorczyk

ESDA2012-82948 89

Identification of a Steady-State Flow in Porous Media Using Artificial Neural Networks

MarekJ. Lefik, Daniela P. Boso, and Bernhard Schrefler

ESDA2012-82953 97

Application of Discrete Element Simulation to the Crushing of a Food Biopolymer Foam for

Mastication ModellingLotfi Hedjazi, Christophe L Martin, Sofiane Guessasma, Guy Delia Valle, an

Remy Dendievel

ESDA2012-82971 99

Multidimensional Hyper-Reduction of Large Mechanical Models Involving

Internal Variables

David Ryckelynck

ESDA2012-83009 107

Goal-Oriented Control of Finite Element Models: Recent Advances and Performances on

3D Industrial ApplicationsLudovic Chamoin, Pierre Ladeveze, and Florent Pled

ADVANCED SIMULATION-BASED ENGINEERING SCIENCES

ESDA2012-82107 109

Numerical Simulation of the Cold Spray Deposition Process for Aluminium and Copper

Jing Xie, Daniel Nelias, Helene Waiter-le-berre, Yuji Ichikawa, and Kazuhiro Ogawa

ESDA2012-82192 113

Integrating Vehicle Body Concept Modelling and Flexible Multi-Body Techniques for

Ride and Handling Simulations

M. Carpinelli, D. Mundo, T. Tamarozzi, M. Gubitosa, S. Donders, and W. Desmet

vi

ESDA2012-82246 123Uncertainty Quantification in Computational Nonlinear Elasticity

E. Capiez-Lernout, C. Soize, and M.-P. Mignolet

ESDA2012-82252133

Optimal Spring Balancing Cylinder Design of an Industrial Robot Using Multi-Disciplinaryand Multi-Objective Optimization

Jakob Westrom, Xiaolong Feng, Hans Andersson, and Stefan Lunderius

ESDA2012-82260141

A Study on the Dynamic Load Simulation for a Crawler Excavator ConsideringGround Effect

Seongpil Yang, Mooseung Kim, Donghyeon Hwang, and Panyoung Kim

ESDA2012-82281. 147

Assessment of Modal Strain Energy Method: Advantages and LimitationsHasan Koruk and Kenan Y. Sanliturk

ESDA2012-82298 155Evaluation of Drivers' Attention Level by a Driving Simulator

Riccardo Bartolozzi and Francesco Frendo

ESDA2012-82301167

A Regression Based Non-Intrusive Method Using Separated Representation forUncertainty Quantification

Prashant Rai, Mathilde Chevreuil, Anthony Nouy, and Jayant Sen Gupta

ESDA2012-82304175

Proper Generalized Decomposition to Solve a 2D Coupled Heat-Diffusion ProblemT. L. Nguyen, M. Beringhier, and J. C. Grandidier

ESDA2012-82331 177A Parallelized Node-Centered Finite Volume Method for Computing Radiative Heat Transferon 3D Unstructured Hybrid Grids

Georgios N. Lygidakis and loannis K. Nikolos

ESDA2012-82344187

Optimization of the Global Static and Dynamic Performance of a Vehicle Body by Means of

Response Surface Models

Pavlina Mihaylova, Alessandro Pratellesi, Niccold Baldanzini, and Marco Pierini

ESDA2012-82389197

Multiscale Model Reduction for the Solution of Stochastic Partial Differential EquationsWith Localized Sources of Uncertainties

Elias Safatly, Mathilde Chevreuil, and Anthony Nouy

ESDA2012-82407205

PGD-BEM Applied to the Nonlinear Heat EquationPierre Joyot, Gael Bonithon, Nicolas Verdon, Francisco Chinesta, and Pierre Villon

vii

ESDA2012-82460 215

Real-Time Control of the Heating of an Airfoil

Francoise Retat-Masson, Francisco Chinesta, Adrien Leygue, Elias Cueto, Laurent Dala,

and Craig Law

ESDA2012-82483 217

Parametric Shape and Material Simulations for Optimized Parts DesignB. Bognet, A. Leygue, F. Chinesta, and F. Bordeu

ESDA2012-82484 219

PGD for Solving the Biharmonic EquationGuangtao Xu, Francisco Chinesta, Adrien Leygue, and Michel Visonneau

ESDA2012-82503 225

On a RSM Approach to the Multihead Weigher Configuration

Alessia Beretta and Quirico Semeraro

ESDA2012-82506 235

A Novel Proper Generalized Decomposition (PGD) Based Approach for Non-Matching Grids

S. Mohamed Nazeer, Francisco Chinesta, and Adrien Leygue

ESDA2012-82524 241

Efficient Reduced Simulation of Shell Structures With a Full Description of the Thickness:

Application to CompositesEtienne Pruliere

ESDA2012-82541 247

Real-Time Simulation for Virtual Surgery in a PGD Framework

Siamak Niroomandi, Felipe Bordeu, Iciar Alfaro, David Gonzalez, Adrien Leygue,Elias Cueto, and Francisco Chinesta

ESDA2012-82546 253

Improving Trajectory Tracking Performance of a 2 DOF Parallel Kinematic ManipulatorWith Flexible Links

Hermes Giberti, Simone Cinquemani, and Stefano Ambrosetti

ESDA2012-82552 263

Advanced Optimization of Industrial Large-Scale Roll-to-Roll Systems Under Parametric

Uncertainties

J. Frechard and D. Knittel

ESDA2012-82595 271

Energy of Vibroacoustic Signal as Parameter of Logistics Model of the Tooth's Crack

DevelopmentStanislaw Radkowski and Robert Guminski

ESDA2012-82738 273

The Role of Placental Locations on Fetus Mortality in Road Traffic Accidents

Moustafa Moustafa, B. Serpil Acar, and Memis Acar

viii

ESDA2012-82785279

Sensitivity Analysis of a Solar Cooling SystemBlaise Letexier, Olivier Marc, Jean-Philippe Praene, and Franck Lucas

ESDA2012-82798289

New Designs of Industrial Accumulators for Elastic Webs: Structures ComparisonDavid Kuhm and Dominique Knittel

ESDA2012-82942297

First Steps of Crack Initiation and Propagation in Fatigue of FCC Crystals Studied byDislocation Dynamics

C. Depres, G. V. Prasad Reddy, L Tabourot, R. Sandhya, and S. Sankaran

ESDA2012-83002307

Tolerance Analysis of Compliant Assemblies Using FEM Simulations and ModalDescription of Shape Defects

Alain Stricher, Laurent Champaney, Francois Thiebaut, Benoit Fricero, andNicolas Chevassus

ESDA2012-83003315

The Galerkin Lumped Parameter Method for Thermal ProblemsAlfredo Bermudez and Francisco Pena

ESDA2012-83008321

A Data Compression Approach for PGD Reduced-Order ModelingDavid Neron and Pierre Ladeveze

ESDA2012-83010325

Task Based Pose Optimization of Modular Mobile ManipulatorsLiang He, Sean Phillips, Steven Waslander, and William Melek

VIRTUAL AND AUGMENTED REALITYESDA2012-82417

335Visualization of Urban Prediction Using Augmented MapsSandy Martedi, Pega Sanoamuang, Sebastien Callier, Milica Muminovic, and

Hideo Saito

ESDA2012-82592341

Virtual Reality Interfaces Applied to Web-Based 3D E-CommerceUnai Elordi, Alvaro Segura, Jon Goenetxea, Aitor Moreno, and Jon Arambarri

ESDA2012-82594351

Augmented Reality Based Maintenance Within Virtual Environments

Ralph Stelzer, Erik Steindecker, Bernhard Saske, and Stefanie Lassig

ESDA2012-82608359

View-Dependent Rendering to Enhance Natural Perception for Augmented RealityWorkstations

Rafael Radkowski and James Oliver

ix

ESDA2012-82769 369

A 3D-GIS Updating Method With Interaction in an Urban Environment

Ruijun Liu, Myriam Servieres, and Guillaume Moreau

ESDA2012-82794 375

The MobilAR Robot, Ubiquitous, Unobtrusive, Augmented Reality Device

Emmanuel Bernier, Ryad Chellali, and Indira Mouttapa Thouvenin

ESDA2012-82946 383

Improving Quality of Train Interiors Through a VR-Based Participative Design Approach

Giuseppe Di Gironimo, Mariano Guida, Antonio Lanzotti, and Amalia Vanacore

ESDA2012-82967 395

Training With Augmented Reality on Engineering Degrees

Cristina Roca Gonzalez, Melchor Garcia Domfnguez, Jorge Martin-Gutierrez,

Manuel Contero, and Mariano Alcaniz

ESDA2012-82993 403

VISIONAIR: A European Infrastructure to Support Research Based on Visualization and

Interaction TechniquesFrederic Noel

APPLIED SOLID MECHANICS AND MATERIAL PROCESSING

ESDA2012-82026 409

Dynamic Stability of Axially Moving Plates With Periodically Varying Speeds Under

Partially Distributed Edge Tensions

T. H. Young, S. J, Huang, and A. C. Liu

ESDA2012-82070 417

Experimental Analysis of Ring Stiffnesses of Pipes, Made of High Density Polyethylene,due to DIN 16961-2:2010-03 Standard

/. Mehmet Palabiyik, A. Orhan Yavuz, Zafer Gemici, and Isminur Gdkgdz

ESDA2012-82120 421

Effect of Plastic Anisotropy on the Collapse Load and the Distribution of Residual Stresses

and Strains in a Thin Disk Subject to Thermo-Mechanical Loading

Sergei Alexandrov

ESDA2012-82121 423

Analysis on the Temperature Rise Produced by Plastic Deformation Heat for Nanoscale

Orthogonal Cutting of Copper WorkpieceZone-Ching Lin, Ying-Chih Hsu, and Liang-Kuang Chen

ESDA2012-82123 431

Theoretical and Experimental Vibration Analyses of Trapezoidal and Sinusoidal

Corrugated Plates

Adil Yucel and Alaeddin Arpaci

x

ESDA2012-82330439

Numerical Simulation Based on Meshless Formulation: Application to 2D Solid MechanicsY. Ghozzi, C. Labergere, and P. Villon

ESDA2012-82364449

Numerical Modeling of the Dynamic Behavior of Shredder Hammers and Correlation WithMaterial Damage

Eugenio G. M. Brusa, Nicola Bosso, and Stefano Morsut

ESDA2012-82366459

Electromechanical Coupled Response of the AC Electric Arc Furnace Structures During theScrap Melting Process

Eugenio G. M. Brusa, Nicola Bosso, Nicold Zampieri, Stefano Morsut, andMaurizio Picciotto

ESDA2012-82397469

Optimum Mandrel Configuration for Efficient Down-Hole Tube ExpansionTasneem Pervez, Omar S. Al-Abri, Sayyad Z. Qamar, and Asiya M. Al-Busaidi

ESDA2012-82488479

Mixed Experimental and Numerical Study of Steel Ferrule Forming by Low-ContactDeformation Process

J. Raujol-Veille, F. Toussaint, L Tabourot, Mathieu Vautrot, and P. Balland

ESDA2012-82517485

Payne Effect in Filled Nitrile Rubber Submitted to Cyclic LoadingsPierre P. Gamier, Jean-Benoit J. B. Le Cam, and Michel M. Grediac

ESDA2012-82674491

Experimental Investigation of High Density Polyethylene Yield Surface UnderBiaxial LoadingKamel Hachour, Meziane Aberkane, and Rabah Ferhoum

ESDA2012-82748497

Lifetime Prediction of Rocket Combustion Chamber Wall by Means of ViscoplasticityCoupled With Ductile Isotropic Damage

Vivian Tini, Ivaylo Vladimirov, and Stefanie Reese

ESDA2012-82759503

Natural Element Simulation of Extrusion of Hollow ProfilesIciar Alfaro, Francesco Gagliardi, Francesco Greco, Luigino Filice, and E. Cueto

ESDA2012-82766509

Finite Strain Constitutive Model of Evolving Elastic and Plastic Anisotropy by Means ofStructure Tensors

Ivaylo N. Vladimirov and Stefanie Reese

ESDA2012-82777519

Some New Theoretical Results for Orthotropic Inflatable Beams

Quang Tung Nguyen, Jean-Christophe Thomas, and Anh Le Van

xi

ESDA2012-82797 529

Non-Associative Finite Strain Plasticity Coupled With Anisotropic Ductile Damage for

Metal FormingT. Dung Nguyen, Houssem Badreddine, and Khemais Saanouni

ESDA2012-82821 535

On the Thermodynamic Coupling in the Continuum Theory of Defects

Johannes Schnepp

ESDA2012-82900 543

Finite Element Analysis of the Influence of the Material Constitutive Law Formulation on

the Chip Formation Process During a High Speed Metal CuttingAdinel Gavrus, Pascal Caestecker, and Eric Ragneau

ESDA2012-82928 553

Elastoplastic Nonlocal Micromorphic Formulations With Damage Gradient

M. Hamed and K. Saanouni

ESDA2012-82931 561

Modelling of Tubes Magnetic Pulse WeldingA. Guglielmetti, N. Buiron, D. Marceau, M. Rachik, and C. Volat

ESDA2012-82964 573

A Continuum Damage and Failure Model Based on Stress-State-Dependent Criteria

Michael Brunig, Steffen Gerke, and Vanessa Hagenbrock

ESDA2012-82981 583

An Adaptive Remeshing Procedure for Modeling the Clinch Forming Process

Abdallah Sahyoun, Alain Rassineux, Jean-Marc Roelandt, Carl Labergere, and

Khemais Saanouni

ESDA2012-82995 589

Application of an Advanced GTN Model

Joseph Fansi, Anne-Marie Habraken, Tudor Balan, Xavier Lemoine, Caroline Landron,

Eric Maire, Olivier Bouaziz, and Mohamed Ben Bettaieb

DYNAMICAL SYSTEMS AND CONTROL

ESDA2012-82061 599

Model Order Reduction for Stochastic Optimal Control

Ngoc-Hien Nguyen, Karen Willcox, and Boo Cheong Khoo

ESDA2012-82063 607

Modeling and Control of Flexible Second Order Systems With Damped Boundaries

Lea Sirota and Yoram Halevi

ESDA2012-82066 615

Minimum Energy Control of Redundant Cartesian ManipulatorsYoram Halevi, Emanuele Carpanzano, and Giuseppe Montalbano

xii

ESDA2012-82080623

Numerical Simulation of Well Trajectory While Drilling Isotropic and AnisotropicFormations

Vadim Tikhonov, Khaydar Valiullin, and Lev Ring

ESDA2012-82089631

A Comparison of Intelligent PID Position Controllers With Autotuners for a

Pneumatic SystemBehrad Dehghan and Brian W. Surgenor

ESDA2012-82102639

Dynamic Analysis of a Bladed Balance Ring DeviceLeonardo Urbiola-Soto, Marcelo Lopez-Parra, and Francisco Cuenca-Jimenez

ESDA2012-82118651

Modelling and Control of a Hydraulically Actuated Shaking Table Employed for VibrationAbsorber Testing

Stefano Pagano, Riccardo Russo, Salvatore Strano, and Mario Terzo

ESDA2012-82143661

Modelling of an Unconventional AirshipSaid Chaabani, Naoufel Azouz, Jean Lerbet, and Azgal Abichou

ESDA2012-82154669

A Stability Analysis of the Wheel ShimmyGiandomenico Di Massa, Stefano Pagano, Salvatore Strano, and Mario Terzo

ESDA2012-82164679

Path Following Performance of Narrow Tilting Vehicles Equipped With Active SteeringJames W. Robertson, Jos Darling, and Andrew R. Plummer

ESDA2012-82182687

Real-Time Roll Angle Estimation for Two-Wheeled VehiclesRoberto Lot, Vittore Cossalter, and Matteo Massaro

ESDA2012-82184695

Output-Only Modal Analysis of an Internal Unreachable Module Embedded in a SpaceElectronic Equipment

Lassaad Ben Fekih, Christophe De Fruytier, Georges Kouroussis, David Wattiaux, andOlivier Verlinden

ESDA2012-82250705

Vibration Identification of Gasoline Engine PartJiuk Chang, Sangkwon Lee, Jongho Park, Byunghyun Kim, and Hongseok Park

ESDA2012-82266709

Tracking Control for Switched Nonlinear Systems Subject to Time-VaryingOutput Constraints

Ben Niu, Georgi M. Dimirovski, and Jun Zhao

xiii

ESDA2012-82282 717

Wheel Shimmy Experimental InvestigationDomenico de Falco, Giandomenico Di Massa, and Stefano Pagano

ESDA2012-82288 727

Hysteresis Switching Design for Stabilization of Switched Neutral Systems Using MultipleLyapunov Functionals

Tai-Fang Li, Ceorgi M. Dimirovski, and Jun Zhao

ESDA2012-82295 733

Synthesis and Optimization of Transient Performances for Underdamped Second-Order

Linear System Based on the Switching Control StrategyQingyu Su, Georgi M. Dimirovski, and Jun Zhao

ESDA2012-82340 741

Safety Protection Control for the Aeroengines via Switching StrategyChao Chen, Georgi M. Dimirovski, and Jun Zhao

ESDA2012-82471 749

Effects of Actuators and Sensors Position on Independent Modal Control Performance

Simone Cinquemani and Ferruccio Resta

ESDA2012-82474 759

Fuzzy Hybrid Control of Off-Road Vehicle Suspension Fitted With Magnetorheological

DampersW. G. Ata and S. O. Oyadiji

ESDA2012-82535 '. 767

Exact Null-Controllability of Abstract Evolution Equations With Boundary Input Operatorsby Smooth Control

B. Shklyar

ESDA2012-82545 775

Control Algorithms of the Longitude Motion of the Powered ParagliderYannickAoustin and Yuri Martinenko

ESDA2012-82555 785Nonlinear Modeling and Control of a 3 DOF HelicopterAbdelhamid Chriette, Franck Plestan, and Marcin Odelga

ESDA2012-82602 795

Improving the Performance of Resonant Controls for Vibration Suppression Using a

Negative Derivative FeedbackGabriele Cazzulani, Ferruccio Resta, and Francesco Ripamonti

ESDA2012-82603 801

A Real-Time Algorithm for Fault Detection in Construction MachineryG. Cazzulani, S. Moschini, F. Ripamonti, and F. Resta

xiv

ESDA2012-82662811

Simulation Technology of Self-Induced Vibration in a Metal Pushing V-Belt CVTToshihiro Saito

ESDA2012-82673819

Optimized Control Strategy Based on the Driving Cycle Type for a Hydraulic Hybrid BusAH Safaie, Vahid Esfahanian, Mohammad Reza Ha'iri-Yazdi, Mohsen Esfahanian,Masood Masih Tehrani, and Hassan Nehzati

ESDA2012-82736, 829

Experimental Analysis and Simulation of the Dynamic Response of a Propeller PitchChange Actuator

Maxime Leclercq, Frangois Malburet, and Philippe Veron

ESDA2012-82778839

Adaptive Second Order Sliding Mode Control: Application to Position and Force Control ofElectro-Pneumatic Actuators

Mohammed Taleb and Franck Plestan

ESDA2012-82819847

Effects of Piezoactuator Failure on Active Control of Beam VibrationMarek Pietrzakowski

ESDA2012-83013853

The Dynamics of a Bi-Stable Energy Harvester: Exploration via Slow-Fast Decompositionand Analytical ModelingNadav Cohen and Izhak Bucher

ESDA2012-83014861

An Optimal Waving Device Utilized in Micro Swimmer/Pump: Analytical, Numerical andExperimental Analysis

Eyal Setter and Izhak Bucher

Author Index869

xv