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6th European LS-DYNA Conference

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 ...
Using LS-Dyna as an Aid to the Inclusive Design of Child Resistant Closures
Joe Luxmoore, Dr. Alaster Yoxall - University of Sheffield
The population of most developed countries is ageing. Despite continuing medical advances, ageing brings with it a host of issues, not least a loss in strength and dexterity. One major area of concern is the ability of elderly consumers to access packaged goods such as food and medicines. In previous studies, the authors developed an LS-Dyna model of a human hand that was used to investigate the effect of physical dimensions and the choice of ...
Accurate and efficient dummy models for occupant safety design
 
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 ...
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 ...
Modelling Carpet for Use in Occupant Crash Simulations
Dylan Thomas - Honda R&D Americas
Prediction of occupant injury using crash simulations can require numerical representation of materials that are not normally included within the structural model. Intuitively, it makes sense that the carpet would be required to predict the tibia index during frontal crash events; however, there appears to be little published on the topic. The tibia index is an injury criteria that needs to be predicted during IIHS frontal offset occupant ...
New developments in LS-OPT Version 3.2
Nielen Stander, Willem Roux - Livermore Software Technology Corporation
An overview of LS-OPT features is given with special emphasis on the major new optimization features available in LS-OPT Version 3.2. These include GUI support for parameter identification, confidence intervals for individual optimal parameters, point plotting as an enhancement to 3-D metamodel plotting, matrix expressions, coordinatebased result extraction and retry features for job distribution
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 ...
ROBUST PARAMETER DESIGN IN LS-OPT
Willem Roux - LSTC
Robust parameter design creates designs insensitive to the variation of specific inputs. The paper discusses the robust parameter design capability within the context of its implementation in LS-OPT version 3.2. The paper provides the following details: the fundamentals of robust parameter design, the design of experiments based methodology used in LS-OPT, and an example problem.
ANSA PRE PROCESSING FOR LS-DYNA
Alexandros Kaloudis - BETA CAE Systems SA
 
Current features and developments of LS-PREPOST
P. Ho - Livermore Software Technology Group
 
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 • ...
Interface ANSYS Workbench for LS-DYNA
M. Hörmann - CADFEM GmbH
 
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, ...
New Developments in the Compression of LS-DYNA Simulation Results using FEMZIP
Rodrigo Iza Teran, Clemens-August Thole, Rudolph Lorentz - Fraunhofer Institute for Algorithms and Scientific Computing SCAI
The standard usage of simulation as part of the automotive design process and increased computer power has increased the demand on archiving resources. This data may be reused several times during the development process and reused later for new models. Compression of the simulation results reduces both the archive size and the access times. This is why FEMZIP was developed several years ago. FEMZIP was specially designed for the compression of ...
Practical Optimization for Automotive Sheet Metal Components
Xiao Chen, Omar Ghouati - Ford Research and Advanced Engineering Europe
Forming simulation has now reached an acceptable level of accuracy. It is possible to predict the hardening, the thinning and required forces for sheet metal stamped parts and it is also possible to predict the geometrical defects such as springback, wrinkling and surface appearance problems. Sheet metal forming can therefore be used in a closed loop to help design of parts and required tools in order to achieve a pre-defined geometry and ...
PROBABILISTIC ANALYSIS OF UNCERTAINTIES IN THE MANUFACTURING PROCESS OF METAL FORMING
H. Müllerschön, D. Lorenz - DYNAmore GmbH
W. Roux - Livermore Software Technology Corporation
M. Liebscher, S. Pannier - TU Dresden
K. Roll - DaimlerChrysler AG
The purpose of this paper is to account for uncertainties in the manufacturing processes of metal forming in order to evaluate the random variations with the aid of FEsimulations. Various parameters of the Finite-Element model describing the investigated structural model are affected by randomness. This, of course, leads to a variation of the considered simulation responses such as stresses, displacements, and thickness reductions. On this, for ...
Robustness Evaluation Crashworthiness Simulation Results
Johannes Will - DYNARDO GmbH
Uli Stelzmann - CADFEM GmbH
The numerical robustness of simulation results from explicit time integration is an important topic. We know for real world applications of passive safety and crashworthiness that we have some numerical noise, but the interesting question is if that really does influence significantly our simulation results. Furthermore, today the robustness of the designs against naturally given input scatter, in loading conditions, geometry or material become ...
Multi-Scale Modelling of Textile Structures in Terminal Ballistics
Rimantas Barauskas - Kaunas university of technology, Lithuania
An efficient finite element model of the ballistic impact and perforation of the woven fabrics structures has been developed in LS-DYNA. The bullet has been considered as a deformable body in contact with the fabric package presented by interwoven yarn structure. The model of the weave has been created by presenting the multifilament yarns by thin shell elements the thickness of which represents the real thickness of yarns. The total model of ...
Reduction of Acceleration Induced Injuries from Mine Blasts under Infantry Vehicles
Ala Tabiei, Gaurav Nilakantan - University of Cincinnati, USA
Anti tank (AT) mines and improvised explosive devices (IED) pose a serious threat to the occupants of infantry vehicles. The use of an energy absorbing seat in conjunction with vehicle armor plating greatly improves occupant survivability during such an explosion. The dynamic axial crushing of aluminum tubes constitutes the principal energy absorption mechanism to reduce the blast pulse transmitted to the occupant in this investigation. The ...
Simulation of a Mine Blast Effect on the Occupants of an APC
A. Brill, B. Cohen - RAFAEL Ballistic Center, Israel
P. Du Bois, Consulting Engineer, Germany
In this paper the use of LS-DYNA for the simulation of a mine blast load on an armoured personnel vehicle is presented with comparison to a full test. The investigated vehicle is an M113 APC with occupants seated in commercial seats. Different approaches to the numerical analysis of this complicated event are presented and results are compared. In particular the blast load is applied using the standard engineering model (CONWEP) because of the ...
Simulation of Masonry Wall Failure and Debris Scatter
Stuart C. McCallum, BAE Systems - ATC (Filton)
Paul M. Locking, Steve R Harkness, BAE Systems - Land (Shrivenham)
This paper outlines a methodology for the simulation of masonry wall failure and debris scatter. The aim of this work is to develop simulation techniques which can be used to assess and improve the design of building structures subject to high explosive loading. Masonry walls are constructed from bricks that are modelled as individual parts with tiebreak and single surface contact types. A key requirement of this work is to accurately predict ...
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 ...
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 ...
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 ...
MICROSTRUCTURE EVOLUTION AND MECHANICAL RESPONSE IN THE HOT STAMPING PROCESS
Mats Oldenburg, Per Salomonsson - Luleå University of Technology
Paul Åkerström, Greger Bergman - Gestamp Hardtech AB
In the manufacturing of ultra high strength boron steel components with the hot stamping process, it is of great importance that the final product will have the desired material properties. This is especially true for safety related automotive components. Often the preferred microstructure is a mix of martensite and bainite. In this work a model is developed and implemented in order to predict the austenite decomposition into ferrite, pearlite, ...
Simulating the Complete Forming Sequence for a Roll Formed Automotive Bumper Beam
Trevor Dutton, Paul Richardson - Dutton Simulation Ltd
Matt Tomlin, Tom Harrison - Wagon Automotive plc
As part of the development of a new automotive bumper beam, a complete simulation of the entire forming process was carried out using LS-DYNA. The material for the beam was an ultra high strength steel presenting many challenges for the forming process. The sequence of forming operations was roll-forming (including forming a sweep in the initially straight roll-formed section), local annealing, forming of an initiator in the wall of the section ...
Some observations on failure prediction in sheet metal forming
Mats Larsson - Saab Automobile, Sweden
Kjell Mattiasson - Chalmers Univ. of Technology, Sweden
Mats Sigvant -Volvo Cars Manuf. Engng., Sweden
This paper presents results from a FE-study on failure prediction in ductile metal sheets. The studied material, a DP600 dual phase steel, is used throughout the study. The effects of variation of element sizes, material parameters, and friction are shown and discussed. Also results from simulations of in-plane and out-of-plane tests are compared and discussed.
Springback analysis in Andvanced High Strength Steel using a new flexible semi-industrial tool geometry, the flex-rail
A. Andersson - Volvo Cars Body Components, Sweden
The automotive industry is using more and more of Advanced High Strength Steel in order to reduce the weight of the car. Since this will generate more springback, it is of vital importance to be able to predict the amount of springback in the parts. Otherwise, many late changes have to be made in order to fit the parts in their position. In order to increase the ability to understand and test the behavior of the springback in sheet-metal parts, ...
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 ...
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 ...
Performance of LS-DYNA with Double Precision on Linux and Windows CCS
Yih-Yih Lin - Hewlett-Packard Company
Although the majority of LS-DYNA jobs are simulated with single-precision arithmetic, the more accurate and robust double-precision arithmetic has to be used for certain situations. Currently, most public LS-DYNA benchmarks are with single precision and few with double precision. As a result, users often try to extrapolate the performance of LS-DYNA with double precision from that with single precision. This paper shows that such extrapolations ...
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 ...
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 ...
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 ...
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, ...
MODELLING OF MATERIAL BEHAVIOUR AND FRACTURE FOR ALUMINIUM ALLOYS WITH APPLICATIONS TO PLASTIC FORMING AND CRASHWORTHINESS
Odd Sture Hopperstad, Torodd Berstad, Odd-Geir Lademo, Magnus Langseth - Norwegian University of Science and Technology
Constitutive models and failure criteria for aluminium alloys have been formulated and implemented in LS-DYNA for corotational shell elements. The applications are largescale simulations of plastic forming and crashworthiness. The constitutive models include plastic anisotropy, non-linear isotropic and kinematic hardening, strain-rate effects and simple fracture criteria. A non-local instability criterion is used to determine the onset of strain ...
THE ROLE OF CAE MODELLING IN VOLVO SAFETY ENGINEERING
Ingrid Skogsmo - Director Volvo Cars Safety Centre
Safety has been a Volvo cornerstone from its founding in 1927, and has remained a fundamental core value since. Within the Ford Motor Company, Volvo Cars has been appointed Centre of Excellence for safety. Continuous development and expansion of the concept of automotive safety involve visionary ideas build on earlier innovative passive and active safety approaches to deliver new "intelligent" solutions designed to neutralize risks of driver ...
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, ...
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 ...
WATER IMPACT: EXPERIMENTAL TESTS AND NUMERICAL SIMULATIONS USING MESHLESS METHODS
Marco Anghileri, Luigi Castelletti, Edoardo Francesconi - Politecnico di Milano, Italia
The outcomes of a research focusing on water modelling and fluid-structure interaction, are here presented. A number of water impact drop tests using a typical aircraft skin panel were performed. The tests were numerically reproduced modelling the fluid region using the two meshless methods implemented in LSTC/LS-Dyna 971: the Smoothed Particle Hydrodynamics and the Element Free Galerkin method. The accuracy of the models was evaluated referring ...
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 ...
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 ...
SIMULATION OF THE IMPACT ON GROUND OF AIRDROP LOADS TO DEFINE A STANDARD WORST CASE TEST
Yves de Lassat de Pressigny, Thierry Baylot - Centre d’Essais en Vol, Ministère de la Défense, France
The French Flight Test Centre in Toulouse (CEV Tl) made in 2004 prototype simulations of ground impact after airdrop (2d-40, 5th European LS-DYNA users conferences.) Its purpose was to enable the test centre to achieve parametric analyses of the shock level produced by airdrop with a combination of simulation and real tests, which was not feasible with tests only (because of the number of test cases required). Indeed a first proposal with ...
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 ...
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. ...
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 ...
MPP DECOMPOSITION OF A SPH MODEL
Jean Luc Lacome - LSTC Vincent Lapoujade Cril Technology – Groupe Alyotech
SPH, Smoothed Particle Hydrodynamics, is a very efficient tool to model industrial problems where large deformations occur. However, one disadvantage of the SPH technique is the expensive cpu cost compared to standard Finite Elements. Using the MPP version of LS-DYNA allows users to handle large problems (more than a million of particles) in a reasonable time. Due to the meshfree nature of the SPH method, standard decompositions used for finite ...
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 ...
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 ...
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