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6th International LS-DYNA Conference

Design Optimization of the Beagle II Mars Lander Airbags Through Explicit Finite Element Analysis – An Update
Anthony P. Taylor - Irvin Aerospace Inc
The Beagle II Mars Lander is a portion of the European Space Agency (ESA) Mars Express program. Irvin Aerospace Limited, on contract to Martin Baker Aerospace Ltd., will provide the parachutes and airbags for the probe’s landing system. The purpose of the Beagle II Lander is to deliver scientific equipment, which will perform atmospheric and soil experiments focused on identifying signs of life on the Red Planet. To reduce development ...
Shape Optimization Of Instrument Panel Components For Crashworthiness Using Distributed Computing
Alex Akkerman , Ravi Thyagarajan - Ford Motor Company,
Mike Burger, Nielen Stander - Livermore Software Technology Corp.,
Bob Kuhn, Hrabri Rajic - Kuck & Associates, Inc.
The ability to quickly design new vehicles with optimal crashworthiness is a goal of automotive manufacturers. This paper takes steps towards that goal by automating manual design iterations. The crashworthiness of an instrument panel was enhanced using LS-OPT and LS-DYNA. It is shown that: • LS-OPT can modify the shape of non-styled parts in the instrument panel in order to • The design was generated several times faster than with ...
Global and Local Coupling Analysis for Small Components in Drop Simulation
Jason Wu - Motorola
The failure induced in radio/phone drop often associate with the damage of inside small components or its tiny substructures. The difficulty to detect the failure in drop simulation is: i) the right drop-induced shock at the components must come from the simulation at whole- phone model; ii) the required output at the small components needs very fine local mesh, which causes unbearable CPU cost and make the simulation impossible. ...
Preliminary Study of the Behavior of Composite Material Box Beams Subjected to Impact
Jason R. Smith, Lawrence C. Bank, Michael E. Plesha - University of Wisconsin-Madison
LS-DYNA 940.2 was used to study the response of composite box beams subjected to oblique (or inclined) impacts by a rigid cylinder. The square cross-section composite beams were 1000 mm long with 50 mm by 50 mm nominal cross-sectional dimensions. The rigid cylinder had a 50 mm diameter and a 100 mm length and impacted the box beam on the top panel. The composite box beam and the cylinder were modeled with 3 mm thick Belytschko- Tsay shell ...
Implementation of Constitutive Equations for Viscoplasticity with Damage and Thermal Softening into the LS-DYNA Finite Element Code, with Application to Dynamic Fracture of Ring- Stiffened Welded Structures
Ricardo F. Moraes, David W. Nicholson - University of Central Florida
Constitutive equations for a viscoplastic model with damage and thermal softening are implemented in the Finite Element (FE) code LS-DYNA using a User Defined Subroutine UMAT. A modified Johnson-Cook constitutive model, UMAT 15, which accounts for strain rate viscoplastic effects, is used. The Continuum Damage Mechanics (CDM) is based on Bonora formulation (Bonora, 1997). The combined material model, named UMAT 41, is added to the program ...
Implementation of a User Material Routine in 3D-FE Codes for Viscoelastic Modeling and Simulation of Highway and Airport Pavements
W. Uddin, L. Ricalde - The University of Mississippi
Traditional static analysis procedures using linear elastic pavement properties may lead to incorrect structural response analysis of pavements. Many of these procedures do not appropriately consider the effects of dynamic loading and pavement nonlinearities such as joints and cracking. It is imperative to use appropriate and correct material properties for meaningful advanced computer simulations. This paper presents some results of ...
Development of a Wood Material Model For Roadside Safety Applications
Yvonne D. Murray - Aptek Inc
A computationally efficient wood material model is being developed and validated for performing LS-DYNA simulations of vehicle collisions into wooden guardrail posts. Typically, the failure modes and stress-strain relationships of wood depend on the direction of the load relative to the grain and the type of load (tension, compression, or shear). The model includes transversely isotropic constitutive equations and yield surfaces to simulate ...
Scalability of LS-DYNA on SGI Systems
Roger Chu, Guangye Li - SGI
In parallel computation, the scalability of the application software is critical. It is especially important when large number of processors are used. In this paper, we present the scalability results of LS-DYNA on the SGI multiprocessor computer systems. Furthermore, since MPP- DYNA is a domain decomposition based software, data partitioning algorithms play an important role in the scalability of the code. We will show in this paper that ...
Scaling Study of LS-DYNA MPP on High Performance Servers
Youn-Seo Roh - Sun Microsystems, Inc.
With LS-DYNA MPP, scalable SolarisTM operating system and the MPI library, Sun Microsystems’ StarfireTM server proved to be capable of producing a scalable solution for large-scale automotive crash simulation problems. It was found that a proper decomposition plays a significant role in achieving optimal scaling results for large-model, computation- intensive runs. Also, a large amount of external cache memory on the Starfire SMP server was ...
A Performance Study of LS-DYNA on Vehicle Crash Simulation
Yih-Yih Lin - Hewlett-Packard Company
Cing-Dao Kan - The George Washington University
For computer companies to design cost-effective machines for LSTC to optimize the software and for the LS-DYNA user to make an intelligent choice of machines, various factors that affect LS-DYNA’s performance must be investigated and understood. Therefore, we have embarked such an investigation with machines from both Hewlett- Packard and SGI. Many results are reported here. The factors considered include the following: memory systems, SMP ...
Partitioning Effects on MPI LS-DYNA Performance
Jeffrey G. Zais - IBM
The MPI version of LS-DYNA includes several options for decomposition of the finite element model. In this paper, the use of these options will be explored, for both metalforming and automotive crash simulations for input decks with size ranging from small to very large. The effect on elapsed time performance and scalability will be measured for different partitioning options. In addition, performance characteristics of a workstation cluster ...
Piercing of Aluminum Beverage Cans
Brian A. Coon, Phanidhar Anugonda, John D. Reid - University of Nebraska-Lincoln
An LS-DYNA finite element model was developed to analyze the structural behavior of an aluminum beverage can subjected to a piercing load applied to the sidewall of the can. Physical testing was performed to help verify the simulation accuracy. The piercing was intended to simulate the damage to a can that might occur during the manufacturing process. Impacts of 5 m/s and 10 m/s were performed with both blunt (flat) and sharp (45 tip) ...
Sidewall Indentation and Buckling of Deformed Aluminum Beverage Cans
Robert W. Bielenberg - University of Nebraska-Lincoln
Scott H. Magner - University of Nebraska-Lincoln
John D. Reid - University of Nebraska-Lincoln
Previous research has demonstrated that finite element analysis can be used to predict the structural behavior of aluminum beverage cans including the buckling of the sidewall of the can. Buckling of a beverage container can occur when the lid is pressed on dented cans during assembly. The purpose of this research was to simulate the sidewall indentation and the buckling of aluminum cans with a deformed sidewall using LS-DYNA and validate ...
A Validation Case Study: Steel Billet Drop Tests and Simulations as Reported in NUREG/CR-6608
Leonard E. Schwer - Schwer Engineering & Consulting Services
James M. Kennedy - KBS2, Inc.
Before performing safety assessments of spent fuel storage casks in drop and tipover accident simulations, method validation calculations are required. The validation process is outlined by the Nuclear Regulatory Commission (NRC) [Tang, et al., undated], and specifically requires the satisfactory replication of the steel billet drop tests, reported in NUREG/CR-6608 (UCRL-ID-129211) [Witte, et al., 1998]. In addition to reporting the test ...
A COMPARISON BETWEEN EXPERIMENTAL TESTING AND NUMERICAL SIMULATIONS OF IMPACT LOADING ON ALUMINUM AND MAGNESIUM STEERING WHEEL ARMATURES
William J. Altenhof - The University of Windsor
William D. Ames - K.S. Centoco Limited
In the present automotive industry, all corporations are focusing on developing automobiles which are light weight, fuel efficient, conform to a level of safety outlined by government regulations, and are available to the consumer at a reasonable cost. The automobile industry has placed a significant amount of time and research funding into developing vehicles which can meet these requirements. K.S. Centoco Ltd., a steering wheel ...
Finite Element Modelling of Biomechanical Dummies- The Ultimate Tool in Anti-Whiplash Safety Design?
Waldemar Z. Golinski, Richard Gentle - The Nottingham Trent University
Nowadays, people purchasing a new car are no longer simply looking for attractive styling, good performance and an efficient, reliable engine; one of their main concerns is now also the safety of the car. During the last decade, significant progress in improving car occupant safety has been made through the use of safety devices, such as airbags and advanced seat belts, as well as the construction of the car body itself. However, much still ...
Simulation of Structural Latches in an Automotive Seat System Using LS-DYNA
Tuhin Halder - Lear Corporation
Latches play an increasingly vital role in an automotive seat system due to the recent introduction of the mandatory 3-point restraint system for center occupants. Traditionally, latches were designed to carry the seat back load, the head restraint load, and the luggage intrusion load. For the new Seat Integrated Restraint (SIR) systems, latches have to meet a very high load requirement with a very low range of allowable displacement. Hence, ...
Nonlinear Analysis of Copper Water Stop
Lou Pingyi, Cao Deqing - Beijing Engineering Software Technology Co. Ltd.
Copper water stop is used to prevent water seeping through the dam. To get the stress and strain distribution status of water stop, LS-DYNA was used to make a nonlinear analysis. Experiment results and simulation data were tested to be consistent.
The New Incompressible Flow Capabilities in LS-DYNA
Mark A. Christon - Livermore Software Technology Corp.
Over the past year, efforts have been underway to extend LS-DYNA’s extensive list of capabilities to include an incompressible CFD solver. The focus of this paper is on the second-order approximate projection method used in LS-DYNA to solve the time-dependent Navier-Stokes equations. In order to address the computational demands of the implicit pressure field, LS-DYNA relies, in part, upon an A-conjugate projection technique coupled with ...
Simulation of Falling Weight Deflectometer for In-Situ Material Characterization of Highway and Airport Pavements
Waheed Uddin - The University of Mississippi
Nondestructive evaluation of highway and airport pavements is performed by deflection testing, such as a falling weight deflectometer (FWD). Many agencies use FWD deflection data to backcalculate pavement moduli using subjective inputs and forcing the moduli within a pre-selected range for each material. The failure of many pavement projects can be attributed to the uncertainties in these material inputs. The use of static elastic layered ...
High Efficient and Powerful Integrated Design Support System "DYNA-Works”
Fuminori Oshita, Osamu Kunieda - The Japan Research Institute, Ltd. (JRI)
Nowadays, the CAE models are getting larger and more complicated. On the other hand, the simulation software including FEM codes, PRE-processors and POST-processors, must be quicker, more accurate and also easy to be used by various level customers. The authors introduce the developing high efficient and powerful design supporting system "DYNA-Works, completely specialized to LS-DYNA.” In this system, besides the general pre-post ...
Optimization of Nonlinear Dynamical Problems Using Successive Linear Approximations in LS-OPT
Nielen Stander - Livermore Software Technology Corporation,Livermore, CA
Rudolf Reichert, Thomas Frank - DaimlerChrysler, Stuttgart, Germany
This paper focuses on a successive response surface method for the optimiza- tion of problems in nonlinear dynamics. The response surfaces are built using linear mid-range approximations. To assure convergence, the method employs two dynamic parameters to adjust the move limits. These are determined by the proximity of successive optimal points and the degree of oscillation, respective- ly. Three diverse examples namely in impact design, ...
Parameter and Optimization Studies for Crashworthiness Design using LS-DYNA and the Altair StudyWizard
U. Schramm, H. Thomas, K. Hayes - Altair Engineering Inc., Troy, MI
In the automotive industry the crashworthiness of a design is of special interest. Non-linear finite element analysis, such as in LS-DYNA, is applied to predict the structural responses. Conclusions from these computations can lead to significant design modifications. Usually, intuition leads the iterative process of finding the best design. It is often hard to determine these design modification from the analysis results. In some cases many ...
Application of LS-DYNA and MADYMO Coupled Model for Simulating an Offset Frontal Crash Scenario
Gunasekar T. J., Mostafa Rashidy - EASi Engineering
Norman Ludtke - Ludtke and Associates
Bruce Spinney - NHTSA
A full vehicle finite element model of the 1995 Chevrolet Lumina validated in full frontal impact was used to simulate a frontal offset impact. The tibia index injury criteria set forth in the European Directive 96/79 were used to assess the injury indices of the occupant in frontal offset computer simulation. Based on the injury predictions from the baseline model, a structural modification to vehicle was made in order to reduce the tibia ...
Integration of Finite Element Analysis (LS-DYNA) with Rigid Body Dynamics (ATB) for Crash Simulation
Bhavin Mehta, Shr-Hung Chen, Srikanth Patlu, Prasad N. Petkar, Robert L. Williams - Ohio University
Lee P. Bindeman - LSTC
James M. Kennedy - KBS2 Inc.
Joseph Pellettiere - Wright-Patterson Air Force Base
This paper describes the Integration of ATB (Articulated Total Body), a rigid body dynamics program and LS-DYNA, a finite element analysis program for PC-based occupant/seat restraint modeling. The integration of ATB and LS-DYNA provides a single simulation tool with the advantages of each individual code. The results of several cases and validation are also described in detail. The output of the coupled software is found to be consistent ...
Polyurethane Material Models for Simulating Leg-Form Impact in Explicit Transient Dynamics
Joe Hassan - DaimlerChrysler
Peter Schuster, G. Frederick - Ford Motor Company
Modeling of foams has become a very important task for automobile engineers due to the fact that compressible plastic foams are used throughout the interior and bumper systems of modern automobiles for safety enhancement and damage prevention. To date, most work has focused on predicting foam performance up to approximately 80% compression. However, in certain cases, it is important to predict the foam under maximum compression, or ...
Virtual Reality Visualization (VRV) of Realistic Weapons Effects Predicted Using LS-DYNA
David W. Nicholson – University of Central Florida, Orlando,
Ricardo F. Moraes - Major of the Army of Brazil
Eduardo Divo, Brian Cahill – Dual Incorporated
A prototype of low cost system is described for visualization of realistic weapons effects experienced by targets undergoing blast and impact, to be used in training of personnel for livefire environments. The system is based on integrating two tools: (a) The Finite Element (FE) impact code LS-DYNA (b) A Virtual Reality Visualization (VRV) system The VRV system was recently developed by DUAL Incorporated of Lake Mary, ...
ALE and Fluid-Structure Interaction Capabilities in LS-DYNA
Lars Olovsson - Livermore Software Technology Corporation
M’hamed Souli - Universite d’Artois
A new Eulerian-Lagrangian coupling algorithm and improved multi-material ALE- capabilities have made LS-DYNA an efficient tool for analyzing large deformation processes, such as bird strike events and forging operations. This paper contains two example problems that illustrate the current features of the code.
Simulation and Validation of UNDEX Phenomena Relating to Axisymmetric Structures
R. Boyd - Altair Engineering Ltd
R. Royles - University of Edinburgh
K. M. M. El-Deeb - Linear & Non-linear Structural Dynamics Ltd
Numerical modelling of underwater explosion (UNDEX) loading using LS-DYNA was studied in free field conditions and in relation to an axisymmetric thin shell of revolution - an echinodome in a floating submerged and tethered configuration. The formulation utilised was multi-material arbitrary Lagrangian Eulerian. Based on preliminary modelling, backed by existing data, numerically reproducible experiments were designed for validation ...
Simulating the Motion of Heart Valves Under Fluid Flows Induced by Cardiac Contraction
Eann A. Patterson, Chris J. Carmody, Ian C. Howard - The University of Sheffield
The motions of natural and replacement valve leaflets are complex functions of a large number of interactions. The principle concern of the simulation work is the investigation of how natural valves operate whilst attached to a deformable aorta close to its connection with the left ventricle. This involves the interaction of a fluid flow with soft, highly deformable structures. LS-DYNA was used to analyse the system using a series of models ...
A Toolbox for Validation of Nonlinear Finite Element Models
Dr. Mark C. Anderson, Timothy K. Hasselman - ACTA Inc.
John E. Crawford - Karagozian & Case Structural Engineers
With increasingly powerful computational resources at our disposal, it is becoming common- place to use analytical predictions in lieu of experimentation for characterization of physical systems and events. This trend, with its perceived potential for reducing costs, is the basis for the simulation-based procurement initiatives currently gaining momentum within the Gov- ernment and industry. However, a simulation-based approach is often sold ...
Vehicle Dynamic Simulation Using A Non-Linear Finite Element Simulation Program (LS-DYNA)
G. S. Choi, H. K. Min - Kia Motors Technical Center
The reason manufacturers invest their time and money in order to improve the performance of dynamic characteristics, fatigue stiffness, NVH and crash safety during the process of vehicle development is directly linked to their competitiveness. Due to the rapid development of the computer CPU and application software, it is possible to perform dynamics analysis and durability design using CAE tools before making a prototype vehicle to ...
Pedestrian Protection: Use of LS-DYNA to Influence Styling and Engineering
Bhavik R. Shah, Richard M. Sturt - Ove Arup & Partners,
Aram Kasparian - Arup
This paper describes the use of LS-DYNA for pedestrian protection analysis. A testing procedure has been documented, that may form the basis of proposed future legislation in Europe. Testing is already carried out regularly as part of the European New Car Assessment Program. Large-scale changes in current styling and engineering practices are needed to pass the tests; often, such changes can be accommodated only if identified at concept or ...
Virtual Proving Ground – A CAE Tool for Automotive Durability, Ride & Handling and NVH Applications
Arthur Tang, Nasser Tamini, David Yang - Engineering Technology Associates, Inc.
The Virtual Proving Ground approach has been developed for simulation of dynamic nonlinear events as applied to automotive durability, ride & handling and noise/vibration/harshness applications. This finite element analysis technique provides a unique method to create and analyze vehicle system models, capable of including vehicle suspensions, powertrains and body structures in a single simulation. Through the development of this ...
VALIDATED CRASH SIMULATION OF THE MOST COMMON GUARDRAIL SYSTEM IN THE USA
Jin Wu - University of Cincinnati
Ala Tabiei Director CENTER OF EXCELLENCE IN DYNA3D ANALYSIS Department of Aerospace Eng. & Eng. Mechanics University of Cincinnati The subject of this investigation is the development of an accurate simulation of a truck impacting a strong-post w-beam guardrail system, the most common system in the USA. Detailed methods for system simulation are proposed and three major issues, which ...
On Applications of Adaptive Strategies for General Shell Structures in Crashworthiness Analysis Using LS-DYNA
Karl Schweizerhof - CAD-FEM GmbH
T. Münz, O. Graf, M. Walz - CAD-FEM GmbH
Chen Tsay, J. O. Hallquist - Livermore Software Technology Corporation
Adaptive strategies are nowadays applied in a rather standard fashion in linear static analyses where reliable global and local estimators are available for many problems [22],[23],[5]. Con- siderable progress has been achieved for nonlinear problems [14], [4][8][9][13][17], also in- volving contact [21], because fairly reliable estimators exist, resulting in efficient procedures. However, for transient loading only limited success has been ...
Educational and Research Issues Concerning Virtual and Real Forming of Sheet Metal
Raghu Echempati, Sarang Likhite - Kettering University
The aim of this paper is to discuss the educational issues concerning real and virtual simulation of sheet metals such as steel, magnesium and aluminum. Although expensive, aluminum and magnesium are being viewed as promising candidates in some of the automotive stamping applications. The philosophy explained in this paper deals with providing concurrent experience of real and virtual forming of sheet metals to engineers. There are several ...
Aid Design Die of Auto-Body Using Numerical Simulation of 3-D Sheet Metal Forming Processes
Ninig-an Hu, Ning-yan Zhu - SAE China (Society of Automotive Engineering of China)
It has been well applied in automotive manufacture of China about the technology of the numerical simulation of 3-D sheet metal forming processes during the recent years. Besides helping tool designers and artificers find optimal shapes of technical surface on the die, DYNAFORM is used in the early stages of the auto-body to work over the formability of various parts. In addition to the stamping process, the new forming technologies can ...
Equivalent Drawbead and its Application in Optimization of Autobody Forming Process
Xionghui Zhou, Ziqiang Liu, Zijie Zhang, Junyue Zhang - Shanghai Jiao Tong University
In this paper, the effect of drawbead on autobody panel forming and the theory of equivalent drawbead are discussed. Compared with the effect of real drawbead, the feasibility and essentiality of equivalent drawbead model in process optimization and finite element analysis of sheet forming are pointed out. An example of car inner door panel is presented. By means of eta/DYNAFORM software, a LS-DYNA based sheet metal forming simulation ...
Simulation of Cold Roll Forming of Steel Panels
Fei-chin Jan, Oladipo Onipede Jr. - University of Pittsburgh
This project uses LS-DYNA to simulate the rolling deformation of a flat steel sheet into a panel of particular shape. The process involves the gradual deformation of the steel sheet by passing it through a series of rollers at a constant speed. Each of these sets of rollers is oriented at a slightly different angle to incrementally increase the deformation of the sheet until the desired geometry is obtained in the panel. Since the sheet ...
Effects of Initial Geometrical Imperfection on Square Tube Collapse
Liang Xue, Zhongqin Lin, Zhengxu Jiang - Shanghai Jiao Tong University
Random geometric imperfections are natural in structures. The initial imperfections used to be ignored in structure strength analysis and thus geometric-perfect models were used in most case of numerical simulation. However, collapse of axially compressed square tubes is not such a case. LS-DYNA is used to simulate the effects initial geometrical imperfection has on square tube collapse. This study proves that dynamic progressive buckling of ...
Fan Blade Bird-Strike Analysis and Design
Thomas J. Vasko - Pratt & Whitney
Bird ingestion is a costly and difficult engine test to perform. It is also one of the most challenging and complex analytical investigations in engine design. The capability to model bird ingestion effects is, therefore, critical to the success of any competitive jet engine program. LS-DYNA has been used in the design and analysis of fan blades for bird-strikes. Descriptions of the bird and blade models used in the analyses along with the ...
Analysis of a Propane Tank Truck Impacting a Concrete Column Using LS-DYNA
Clayton F. Heberling - Pressure Sciences, Inc.
Pressure Sciences Inc. used LS-DYNA to model a propane tank truck colliding with a concrete column. The analysis simulates an accident that occurred in 1994 in White Plains, New York. Correlation between the accident and an LS-DYNA analysis of that crash is described. The ultimate purpose of the analyses is to improve the crashworthiness of propane semi-trailers. To address the stiffening effect of the propane fluid, we correlated several ...
Comparison of Two Modeling Approaches for Thin-Plate Penetration Simulation
Norman F. Knight - Veridian-MRJ, USA
Navin Jaunky - Eagle Aeronautics, USA
Robin E. Lawson - FDC/NYMA, USA
Damodar R. Ambur - NASA Langley Research Center, USA
Modeling and simulation requirements for uncontained engine debris impact on fuselage skins are described and assessed using the tied-nodes-with-failure (TNWF) approach and the element-erosion (EE) approach for penetration simulation. The TNWF approach is based on coincident nodes generated in selected regions of the target plate that are tied together using a constraint relation and the target plate is modeled with shell elements. The EE ...
Making FEM Tire Model And Applying It For Durability Simulation
Masaki Shiraishi, Hiroshi Yoshinaga, Naoaki Iwasaki, Sumitomo Rubber Industries - LTD
Kimihiro Hayashi - The Japan Research Institute,Ltd
In recent years, CAE (Computer Aided Engineering) has become very popular for effective development of many industrial products. In the development of automobile, CAE has been applied in many fields. About endurance and fatigue analyses of automobile, it is necessary to simulate the force by road input, and accurate tire model is necessary for this. But the construction of tire is very complicated and its model is so complicated that large ...
Accurate and Detailed LS-DYNA FE Models of the US- and EUROSID: A Review of the German FAT Project
Ulrich Franz, Oliver Graf - CAD-FEM GmbH, Grafing/ Munich, Germany
Finite element side impact dummy models of the USSID and EUROSID are of major interest for industry, as more detailed models are required for better prediction capabilities, but still efficiency has to be maintained to some degree. Both type of models, the so-called FAT- USSID and FAT-EUROSID have been developed by CAD-FEM in cooperation with the German Association for Automotive Research (FAT). The main objective was to achieve highly ...
Study on the Effects of Numerical Parameters on the Precision of Springback Prediction
Zhongqin Lin, Gang Liu, Weili Xu, Youxia Bao - Shanghai Jiaotong University
Accurate prediction of springback is the precondition of controlling the springback. The precision of springback prediction is affected by many parameters in both forming process and springback process. The 2-D draw bending benchmark of NUMISHEET’93 is used as an example to investigate the influencing of numerical parameters in LS-DYNA and LS-NIKE3D, which includes solution approach, dynamic effect, number of the dies’ corner elements ...
ADAPTIVE FINITE ELEMENT SIMULATION OF SHEET METAL FORMING PROCESSES USING GRADIENT BASED INDICATORS
Ramin Moshfegh, Xiangdong Li, Larsgunnar Nilsson, Ramin Moshfegh -Linköping Institute of Technology
Two mesh refinement indicators based on the gradients of effective stresses (GSIG) and effective plastic strains (GEPS), respectively, are proposed for adaptive finite element analysis of the large deformation, quasi-static or dynamic response of shell structures. The mesh refinement indicators are based on equi-distributing the variation of stresses or plastic strains over the elements of the mesh. A program module is developed ...
Computer Simulation of Sheet Metal Forming and Drawbead Effects Using eta/DYNAFORM
Yinghong Peng, Zhaoyuan Wang, Xiongfei Yin, Xueyu Ruan - Shanghai Research Institute of Tool & Die
The kernel technology of a computer simulation system and the general procedure of dynamic simulation in sheet metal forming are presented. As an example, processing parameters of the experimental die of a car inner door panel were optimized with eta/DYNAFORM software. The appropriate round corner of punch, BHF and the correct layout of the drawbead were obtained.
Micromechanics Based Composite Material Model for Impact and Crashworthiness Explicit Finite Element Simulation
Ala Tabiei, Quing Chen - University of Cincinnati
A micro-mechanical model is developed for laminated composite materials and implemented in the explicit finite element method. The objective of this study is to get an accurate and simple micro-model, which can be used in the displacement-based nonlinear explicit finite element code DYNA3D. The micro-mechanical model implemented in the explicit finite element code can be used for simulating the behavior of composite structures under ...
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