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6th European LS-DYNA Conference

A COMPARATIVE REVIEW OF DAMAGE AND FAILURE MODELS AND A TABULATED GENERALIZATION
P.A. Du Bois - Consulting Engineer, Germany
S. Kolling, M. Feucht - DaimlerChrysler AG, Germany
A. Haufe - Dynamore GmbH, Germany
Reliable prediction of damage and failure in structural parts is a major challenge posed in engineering mechanics. Although solid material models predicting the deformation behaviour of a structure are increasingly available, reliable prediction of failure remains still open. With SAMP (a Semi-Analytical Model for Polymers), a general and flexible plasticity model is available in LS-DYNA since version 971. Although originally developed for ...
A Functional Bayesian Method for the Solution of Inverse Problems with Spatio-Temporal Parameters
Zenon Medina-Cetina - International Centre for Geohazards / Norwegian Geotechnical Institute
Roger Ghanem, Amy L. Rechenmacher - University of Southern California
A Functional Bayesian (FB) methodology is introduced for the calibration of constitutive parameters spatially distributed within a model. The probabilistic solution to the inverse problem consists of assimilating the uncertainty captured from the actual material responses into the material parameters. A case study is introduced to illustrate the applicability of the method, where a soil model built in LS-DYNA is parameterized using surface ...
A New Impact Scenario for P-V Tram Certification
M. Anghileri, L. Castelletti, M. Pirola, F. Pistochini, S. Raiti- Politecnico di Milano, Italia
Tram crashworthiness is getting a more and more demanding issue. Simulations carried out to verify that the new tram AnsaldoBreda Sirio-Milano fulfils the prEN 15227 requirements for certification are here described. Besides a new impact scenario with characteristics closer to trams accidents is proposed. Structural enhancements so that the tram fulfils also the more severe impact condition of the new scenario are introduced.
Accurate and efficient dummy models for occupant safety design
 
Advanced Finite Element Model for AE-MDB Side Impact Barrier
M. Asadi , P. Tattersall - Cellbond Composites Ltd.
B. Walker - ARUP Campus (UK)
H. Shirvani - Anglia Ruskin University (UK)
This paper represents a new Finite Element simulation model for AE-MDB v3.9 side impact barrier and proposes a method on creating suitable assumptions and material data. Cellbond AE-MDB barrier investigation was carried out to produce an advanced FE model. Experimental Flat Wall and Offset Pole test results were used to validate the accuracy of the developed models. The explicit LS Dyna 3D code was used to model the geometries, and the Material ...
Advanced Simulations of Cellular Structures with LS-DYNA
Matej Vesenjak, Zoran Ren - University of Maribor
Cellular structures have an attractive combination of physical and mechanical properties and are being increasingly used in modern engineering applications. In this study the influence of different parameters (type of base material, type of pore filler, relative density, size of the cellular structure, strain rate) on behaviour of open- and closed-cell cellular structures under impact loading was investigated by means of computational ...
Advances in Adaptive Thermal-mechanical Metal-forming Simulations in LS-DYNA
Rudolf Bötticher - TMB GmbH
The vision of LS-DYNA is to become multiphysics and adaptive. LSTC endeavours to make the LS-DYNA code as complete, accurate and easy to use as possible. This contribution evaluates the features for adaptive thermal-mechanical simulations that are in recent LS-DYNA versions with a focus on implicit 3D. Implicit solutions do not need mass scaling as explicit forming simulations often use. Implicit element free Galerkin (EFG) elements are ...
AIRBAG SIMULATION WITH LS-DYNA PAST – PRESENT – FUTURE
A. Hirth - DaimlerChrysler AG, Germany
A. Haufe - Dynamore GmbH, Germany
L. Olovsson - IMPETUS Afea AB, Sweden
During the last decade the simulation of the airbag deployment process has become a standard application of explicit finite element codes. At the beginning of the development the focus was to capture the influence and improve the results of dummy impact on fully inflated airbags. Later the deployment kinematics of folded airbags, different folding techniques and vent-hole design became more and more important. With the requirement to comply with ...
ALE Modeling of Surface Waves
AQUELET Nicolas - Livermore Software Technology Corporation
An Arbitrary Lagrange Euler formulation for the propagation of surface waves is developed in LS-DYNA®. The ALE computational time step in this code is divided in two cycles: a Lagrangian cycle in which the mesh follows the material deformation and an advection cycle in which the users through remapping algorithms control the mesh motion. The new feature presented in this paper is one of these remapping algorithms. It enables a Lagrangian ...
ANSA PRE PROCESSING FOR LS-DYNA
Alexandros Kaloudis - BETA CAE Systems SA
 
Application of Shell Honeycomb Model to IIHS MDB Model
Shigeki Kojima - TOYOTA TECHNICAL DEVELOPMENT CORPORATION
Tsuyoshi Yasuki, Koji Oono - Toyota Motor Corporation
This paper describes a new finite element modeling method of Aluminum honeycomb using shell elements. It is our new modeling method that cell size of honeycomb structure is enlarged to increase time step size for FEM analysis, and compressive strength is controlled by thickness of shell elements. New modeling method was applied to IIHS moving deformable barrier model, and side impact analysis with a full vehicle model was performed. The result ...
Concept Design of an A-Pillar Mounted Airbag for Pedestrian Head Protection
Jianfeng Yao, Jikuang Yang - Chalmers University of Technology
Accident investigations have shown that in pedestrian-versus-vehicle accidents, windshield edges, A-pillars, cowls are the main sources for severe head injuries due to their high stiffness. To mitigate head injury severities, it is necessary to improve the safety performance of these structures. An A-pillar mounted airbag system (AMAS) was devised with the aim to prevent head from directly impacting against stiff structures such as A-pillars, ...
Contact and Sliding Simulation of Rubber Disk on Rigid Surface with Microscopic Roughness
Sunao Tokura - JRI Solutions, Ltd.
It is crucial to obtain detailed information about frictional interaction between tire and road surface to estimate performance of vehicle brake system or tire on real road surface. Simulation using Finite Element Method (FEM) in addition to experimental procedure is regarded to be useful to investigate contact behavior between tire and road surface. However, indeed, it is difficult to apply FEM simulation for such a problem since contact and ...
Corpuscular method for airbag deployment simulations
Lars Olovsson, IMPETUSAfea AB
 
Current features and developments of LS-PREPOST
P. Ho - Livermore Software Technology Group
 
Deployment Simulations of Space Webs
M. Gärdsback, G. Tibert - Royal Institute of Technology
 
DEVELOPMENT AND EVALUATION OF A CONTINUUM NECK MUSCLE MODEL
S. Hedenstierna, P. Halldin, K. Brolin - Royal Institute of Technology, Stockholm, Sweden
The Finite Element method is a powerful tool for analyzing the biomechanics of the human body. One area that has attracted increasing attention is the cervical musculature and its influence in neck injury mechanisms. Most cervical FE models of today use spring-elements as muscles and are limited to discrete geometries and nodal output results. A solid-element muscle model however, will improve the geometry and add properties such as tissue ...
DEVELOPMENT OF ADVANCED HUMAN MODELS IN THUMS
Masami Iwamoto, Yuko Nakahira, Atsutaka Tamura, Hideyuki Kimpara, Isao Watanabe, Kazuo Miki - Toyota Central R&D Labs., Inc.
A finite element model of human body called THUMS has been developed to predict gross motions and multiple skeletal injuries of a whole human body during impacts. Recently, we have developed a head/brain model and thoracic/abdominal internal organ models to evaluate more severe injury risks for occupants and pedestrians in automotive accidents. The head/brain model was validated against some test data on translations and rotations of the head ...
Development of BioRID II Dummy Model using Stochastic Methods
Sebastian Stahlschmidt, Bastian Keding, Katharina Witowski, Heiner Müllerschön, Uli Franz - DYNAmore GmbH, Stuttgart, Germany
Consumer and insurance organizations use the BioRID II dummy as test device to assess the risk of whiplash injuries in rear crash scenarios. DYNAmore GmbH developed a finite element model for LS-DYNA of the BioRID II dummy in cooperation with the German Automotive Industry (FAT). The project follows the updated development guidelines of successfully developed models for the FAT in previous projects. This paper describes the applied development ...
Development of validated Finite element model of a rigid truck suitable to simulate collisions against road safety barriers
M. Pernetti - Second University of Naples
S. Scalera - University of Naples "Federico II"
The effectiveness of FEM (Finite Element Method) to improve the crashworthiness, both of the vehicle and of the road safety hardware, has been plainly demonstrated in literature. As well known, such a methodology can be successfully employed (i) as a support to design novel devices and (ii) as a tool to perform parametric studies to assess the influence of different factors. Of course this is possible only when available models are calibrated in ...
Development of validated Finite element model of an articulated truck suitable to simulate collisions against road safety barriers
M. Pernetti - Second University of Naples
S. Scalera, G. Cibllis - University of Naples "Federico II"
Crashworthiness is one of the most important aspect which is taken into account in road design. The effectiveness of Finite Element Method (FEM) to solve major design problems and as a tool to perform parametric studies, has been plainly demonstrated in literature. Of course this is possible only when available models of vehicles and devices are calibrated in a wide range of impact conditions. This research, was intended to develop a well ...
Developments in Occupant and Seat Modelling with Primer 9.3
Miles Thornton, Richard Sturt, Chris Bell - Arup
There is constant pressure to reduce the time needed to process design data into crash results (mesh, assemble, create different crash cases, check, run, post-process). The meshing step has been reduced by batch meshing technology, and progress has been made in several other areas such as automatic post-processing. Attention is now turning to the remaining bottlenecks, which include occupant and seat positioning. These steps require careful ...
DOE SENSITIVITY ANALYSIS WITH LS-OPT AND VISUAL EXPLORATION OF DESIGN SPACE USING D-SPEX
Katharina Witowski, Heiner Muellerschoen, Marko Thiele - DYNAmore GmbH
Uwe Gerlinger - AUDI AG
This paper describes the approach of a DOE (Design of Experiments) sensitivity analysis using LS-OPT in conjunction with AURA for simulating the radiation of a diesel particle filter. The process flow from preprocessing to the visual evaluation of the results using the D-SPEX (Design SPace EXplorer) software is presented. For the purpose of this sensitivity analysis the geometrical arrangement as well as polynomial curves from the AURA input had ...
Effects of Mesh Size and Remapping on the Predicted Crush Response of Hydroformed Tubes
Guillaume D'Amours, Ahmed Rahem - National Research Council of Canada
Robert Mayer - General Motors Technical Center
Bruce Williams - University of Waterloo
Michael Worswick - University of Waterloo
Crashworthiness simulations can be useful tools in vehicle design. According to Du Bois [1], there are many factors which affect the reliability of crashworthiness models. Especially, the mesh size and the mapping of forming results into crash models. Few studies have analyzed the mesh size effect with forming results on the crashworthiness of frame components. This paper presents an analysis of crush response of hydroformed aluminium tubes from ...
Enhancements in dummy model development and outlook
Jim Rasico, Fuchun Zhu, Robert Kant - First Technology Safety Systems, Inc.
It has been almost 11 years since FTSS introduced the Hybrid III 50th dummy finite element model in 1996. From their inception, Finite Element dummy models were constrained in size and accuracy by the computational resources and modeling capabilities of the time. In recent years, the numerical simulation and analysis industry has benefited from the advanced computing technology and finite element modeling techniques. Today the latest ...
ENHANCEMENTS IN DUMMY MODEL DEVELOPMENT AND OUTLOOK
Jim Rasico, Fuchun Zhu - First Technology Safety Systems, Inc., USA
Robert Kant, First Technology Safety Systems Europe, The Netherlands
It has been almost 11 years since FTSS introduced the Hybrid III 50th dummy finite element model in 1996. From their inception, Finite Element dummy models were constrained in size and accuracy by the computational resources and modeling capabilities of the time. In recent years, the numerical simulation and analysis industry has benefited from the advanced computing technology and finite element modeling techniques. Today the latest ...
Evaluation of rail height effects on the safety performance of W-Beam barriers
Dhafer Marzougui, Pradeep Mohan, Cing-Dao (Steve) Kan - The George Washington University, USA
Kenneth Opiela - US Department of Transportation, USA
The objective of this study is to investigate the effect of rail height on the safety performance of G4(1S) w-beam guardrail systems. The study involved three steps. In the first step, a detailed finite element model of the G4(1S) guardrail system was created. The model incorporated the details of the rail, connections, the post, the blockout, and the soil in which the post was embedded. To validate the model of the wbeam guardrail system, a ...
EVOLVING TECHNOLOGY: MULTI-PHASE, MULTIMATERIAL, ALE APPROACH AND TOOL DEVELOPMENT FOR BURIED BLAST SIMULATION
Dr. Rahul Gupta - U.S. Army Research Laboratory Aberdeen Proving Ground
Modeling the response of structures subjected to blast from shallow buried explosives poses a challenge, primarily due to the inherent coupled interaction. The response of the structure affects the surrounding blast pressure field, which in turn, affects the loading on the structure; therefore the problem is coupled in nature. The problem is complicated due to the difference in time scales associated with the blast loading and structural damage. ...
Experience from using recently implemented enhancements for Material 36 in LS-DYNA 971 performing a virtual tensile test
Michael Fleischer - BMW Group
Thomas Borrvall - Engineering Research Nordic AB
Kai-Uwe Bletzinger - Technische Universität München
In today’s automotive industry the development of car bodies considerably depends on the use of computer-aided tools to meet the challenges of rising product complexity and growing number of variants. Today, enabled by modern simulation software, improved material models and numerical methods, simulation has become essential for the evaluation of sheet-metalstamping processes before press tools are manufactured. Though modern material models are ...
Fan Blade Bird Strike Analysis Using Lagrangian, SPH and ALE Approaches
Alexander A. Ryabov, Vladimir I. Romanov, Sergey S. Kukanov - Sarov Engineering Center
Yuriy N. Shmotin, Pavel V. Chupin - NPO Saturn
Fan blade bird resistance is one of the most important certification requirements for modern jet engines. The development test to meet the requirement is difficult and costly experiment. The expenses can be significantly reduced by using the numerical simulation of fan blade bird strike problem in the design of jet engine. The common technique for such simulations is modeling of bird as a solid cylinder or ellipsoid with material properties ...
FE-MODELING OF SPOTWELDS AND ADHESIVE JOINING FOR CRASHWORTHINESS ANALYSIS
A. Haufe , G. Pietsch - Dynamore GmbH, Germany
M. Feucht, S. Kolling - DaimlerChrysler AG, Germany
The increasing demands with regard to the predictive capabilities and the exactness of crash simulations require more and more investigations into numerical models in order to capture the physical behavior reliably. Steps towards this goal are the usage of finer meshes which allow for a better geometrical representation and more sophisticated material models which allow better prediction of failure scenarios. Another important playground ...
FE-MODELLING OF HYDRODYNAMIC HULL-WATER IMPACT LOADS
Ivan Stenius, Anders Rosén - KTH Centre for Naval Architecture
This paper considers finite element modelling of the hydrodynamic loads in hull-water impacts. The commercial FE-code LS-DYNA is used with a multi-material arbitrary Lagrangian-Eulerian formulation and a penalty contact algorithm. The great advantage of this modelling technique is that it enables the modelling of the instantaneous fluidstructure interaction. A difficulty is however the selection of appropriate modelling parameters. A method to ...
Finite element analysis of Polymer reinforced CRC columns under close-in detonation
Benjamin Riisgaard NIRAS Consulting Engineers, Denmark
Anant Gupta, Priyan Mendis, Tuan Ngo - The University of Melbourne
Polymer reinforced Compact Reinforced Composite, PCRC, is a Fiber reinforced Densified Small Particle system, FDSP, combined with a high strength longitudinal flexural rebar arrangement laced together with polymer lacing to avoid shock initiated disintegration of the structural element under blast load. Experimental and numerical results of two PCRC columns subjected to close-in detonation are presented in this paper. Additionally, a LS-DYNA ...
Fluid Structure Interaction for Immersed Bodies
Jason Wang, Hao Chen - Livermore Software Technology Corporation
A new method for automatically constructing the coupling surface along shell edges is developed. By using this new "edge" option together with "shell thickness" option in the *CONSTRAINED_LAGRANGE_IN_SOLID card, we can accurately model problems involving shell structures with leading edges cutting into ALE materials. Engineering problems include bird striking at propulsion system fan blades; helicopter impacting water. This new feature is ...
Forming of alloy plate by underwater shock wave of explosive
K. Kuroda, H. Hamada, H. Hamashima, S. Itoh - Kumamoto University, Japan
The fuel cost and efficiency of the automobile greatly depend on the weight. Researches for light weight automotive components are actively being performed, and automobiles using Aluminium alloys instead of steel are becoming more common. However, Al alloys have limited formability in comparison with steel and its final shape is more limited. We have attempted to improve this limited formability of Al alloys by explosive forming technique, which ...
HIGH VELOCITY IMPACTS SIMULATIONS WITH SPH METHODS IN LS-DYNA
Gilles Mazars, Gabriel Desille, Vincent Lapoujade - CRIL Technology - Groupe ALYOTECH
Christian Durin - CNES
Several high velocity impacts (HVI) can be simulated using the SPH method in LSDYNA. Space debris, whose quantity is on the rise, now pose a major threat to satellites. Effective impact models enable both the development of more efficient protections and the prediction of the damage that an individual HVI will cause to structures. This paper aims to provide advice and words of caution on how to best model such impacts but also presents an ...
HPC Considerations for Scalable Multidiscipline CAE Applications on Conventional Linux Platforms
Stan Posey - Panasas, Inc.
This paper examines HPC workload efficiencies for sample multidiscipline LS-DYNA applications on a conventional HPC Linux platform with proper balance for I/O treatment. Model parameters such as size, element types, schemes of implicit and explicit (and coupled), and a variety of simulation conditions can produce a wide range of computational behavior and I/O management requirements. Consideration must be given to how HPC resources are ...
Image Based Meshing for LS-DYNA
Brian Walker - Arup
Philippe Young - Simpleware
Simpleware provides what is effectively a 3D photocopier: three dimensional replicas can be generated automatically based on scans. In parallel, computer simulations can be used to assess the suitability or performance of objects in operation. Simpleware's technology has opened up FEA and RP manufacturing to a variety of applications and research fields including: • Industrial reverse engineering • Research in materials and composites • ...
Implementation of a material model with shear rate and temperature dependent viscosity
Mathias Vingaard, Benny Endelt, Jesper deClaville Christiansen - Aalborg University
A material model with shear rate and, optionally, temperature dependent viscosity was implemented. Shear rate dependence is expressed with a Yasuda function and temperature dependence with an Arrhenius function. The functions were fitted to viscosity data from oscillatory rheometry of polystyrene. Validation of the viscosity function in the material model was done with a single element with prescribed shear rate and temperature. Steady state ...
IMPLEMENTATION OF A NOVEL SHIP SIDE STRUCTURE INTO A TANKER AND A ROPAX VESSEL FOR INCREASED CHRASHWORTHINESS
Sören Ehlers, Kristjan Tabri, Nicole Schillo, Janne Ranta - Helsinki University of Technology
The energy absorption of a novel ship side structure is numerically analysed. The structure is implemented into an ice going Tanker and a ROPAX vessel. The aim is to evaluate the benefits in crashworthiness of such an application over the existing conventional side structures. The collision simulations are performed with the explicit non-linear solver LS-DYNA up to the point of inner shell breaching. The obtained energy-penetration curves of the ...
Increasing Initial Internal Energy of Air Elements near Explosive for Fluid-Structure Models of a Steel Plate Subjected to Non-contact Explosion
Wen-Chih Li, Wen-Feng Yu, Ding-Shing Cheng - National Defense University
This study was to simulate a steel plate subjected to non-contact explosion by using Arbitrary Lagrangian-Eulerian (ALE) algorithm of the LS-DYNA software. A 3-D Fluid-Structure interaction model was considered. The numerical result would be compared with S.D. Boyd’s experiment, which 250g Pentolite explosive detonated above a 5 mm thick steel plate. The Eulerian mesh for explosive and air and the Lagrangian mesh for steel plate and its ...
Innovative modeling capabilities in virtual.lab in view of cross attribute simulation
Tom Van Langenhove, Cedric Canadas, Nick Tzannetakis, Christophe Liefooghe - LMS International
To meet the challenge to support the development of an ever increasing number of vehicle models and variants with an optimal quality in the constantly decreasing resource and time requirements, companies are forced to increase the integration amongst and impact of the different simulation disciplines in the core vehicle design and engineering process. A proposed methodology is offered by LMS through the LMS Virtual.Lab Software suite proposing ...
Interface ANSYS Workbench for LS-DYNA
M. Hörmann - CADFEM GmbH
 
Investigation into the rising air pressure inside the door during side impacts
Michael Machens - Wilhelm Karmann GmbH
Thomas Wessels - FH Osnabrück
A crucial point in side impacts is the rapid intrusion of the side structure of the door into the passenger compartment. In the initial stage of the crash it is essential to provide sufficient space between occupant and door trim to enable a proper unfolding of the side airbag. This problem can be alleviated by using the rising air pressure inside the door as an additional input for crash sensing. When combined with the common acceleration ...
LANDMINE PROTECTION OF ARMOURED PERSONNEL CARRIER M113
Mads Berg Larsen, Niras Demex, Kasper Cramon Jorgensen
This paper presents numerical analysis and full-scale test of a mine protected armoured personnel carrier M113 subjected to a detonation of a buried 5.56 kg C4 surrogate mine placed under the belly of the vehicle. The protection consists of granulated ceramics (CRUSHMAT) filled within the space between the bottom plate and a reinforced floor. The vehicle structure and mine protection are modelled with Lagrange elements and the mine and ...
LS-DYNA Data Management using Visual-Environment
S.H. Shetty, V. Ganesan, S.C. Sivalingam, E. De Pommery, J.L. Duval - ESI Group
Realistic Simulation is considered to be the most important part of Simulation Based Design (SBD) in the product development cycle. Realistic simulations can not be achieved just by using currently available CAE pre and post processing functionalities alone. Many of the complex requirements of CAE modeling need to be addressed by having a synchronized CAD and CAE environment. CAE analysts need a tool, which will allow them to control variables, ...
LS-DYNA Features for Hot Forming
Arthur Shapiro - LSTC
LS-971 has several features to model the hot forming process. A thick thermal shell formulation for the blank allows modeling a temperature gradient through the thickness. The keyword, *MAT_ADD_THERMAL_EXPANSION, allows calculating thermal strains for all the mechanical material models. A user-defined flag is available to turn off thermal boundary conditions when part surfaces come in contact. A thermal oneway contact algorithm is available to ...
LS-DYNA Performance and Scalability in the Multi-Core Environment
Gilad Shainer - Mellanox Technologies
Efficient data transfer between clustered compute nodes is critical for balanced system performance. In a balanced system, the overall performance is equal to or greater than the sum of its components, while in a non-balanced system, the performance is less than the sum. The challenge of achieving balanced performance becomes more evident in multi-core environments. A multi-core environment introduces high demands on the cluster interconnect and ...
LS-DYNA USED TO ANALYZE THE MANUFACTURING OF THIN WALLED CANS
Joachim Danckert - Aalborg University
The ironing process and the backward can extrusion process are widely used for the manufacturing of thin walled cans. In the ironing process the die is commonly made with a cylindrical die land and in backward can extrusion the punch is commonly made with a cylindrical punch land. LS-Dyna has been used in the analysis of the influence, which the die land and the punch land have. The results suggest that a small misalignment of the die land, ...
LS-OPT based identification of a user defined material model for distortional hardening with application to sheet forming processes with complex strain path changes
Vladislav Levkovitch, Bob Svendsen - University of Dortmund
Sheet metal forming involves large strains and severe strain path changes. Large plastic strains lead in many metals to the development of persistent dislocation structures resulting in strong flow anisotropy. This induced anisotropic behavior manifests itself in the case of a strain path change by very different stress-strain responses depending on the type of the strain path change. While many metals exhibit a drop of the yield stress ...