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ON THE APPLICATION OF LS-OPT TO IDENTIFY NON-LINEAR MATERIAL MODELS IN LS-DYNA
David J. Benson,Morten R. Jensen - University of California, San Diego
Nielen Stander - Livermore Software Technology Corporation
Kenneth J. Craig - University of Pretoria
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A response surface optimization algorithm for structural material or parameter identification is
evaluated. The algorithm used is the Successive Response Surface Method (SRSM) available in
LS-OPT. To illustrate the robustness of SRSM as a material identification tool, two test cases are
presented. The first concerns the identification of the power-law material parameters of a simple
tensile test specimen. The second test case involves the ...
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A MATERIAL MODEL FOR TRANSVERSELY ANISOTROPIC CRUSHABLE FOAMS IN LS-DYNA
Andreas Hirth - DaimlerChrysler
Paul Du Bois, Dr. Klaus Weimar - DYNAmore
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Recently new materials were introduced to enhance different aspects of automotive safety while minimizing the
weight added to the vehicle. Such foams are no longer isotropic but typically show a preferred strong direction due
to their manufacturing process. Different stress/ strain curves are obtained from material testing in different
directions. A new material model was added to the LS-DYNA code in order to allow a correct numerical ...
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Continuous Surface Cap Model for Geomaterial Modeling: A New LS-DYNA Material Type
Leonard E Schwer - Schwer Engineering & Consulting Services
Yvonne D Murray - APTEK, Inc.
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The Continuous Surface Cap Model is a new addition to the LS-DYNA geomaterial modeling library of constitutive
models (Material Type 145). This new model should replace the use of the Geological Cap Model (Material Type
25) for most applications. The Continuous Surface Cap Model maintains all the functionality of the Geological Cap
Model with the addition of the third stress invariant, strain rate effects, and damage modeling. The ...
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Strain Rate Dependent Micro-Mechanical Composite Material Model for Finite Element Impact Simulation
Ala Tabiei, Weitao Yi - University of Cincinnati
Robert Goldberg - NASA Glenn Research Center
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The present study aims at implementation of a strain rate dependent, non-linear, micro-
mechanics material model for laminated, unidirectional polymer matrix composites into the
explicit finite element code LSDYNA. The objective is to develop an accurate and simple micro-
mechanical, rate dependent material model, which is computationally efficient. Within the model
a representative volume cell is assumed. The stress-strain relation ...
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Improving Crash Analysis Through the Estimation of Residual Strains Brought About by Forming Metal
William Broene - Brown Corporation of America
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This paper describes a method that can be used to estimate the residual strains from the forming of sheet metal
without running forming simulations. For a first-order crash analysis, using estimated residual strains rather than the
strains reported from several forming simulations increases the speed of the design process. The method estimates
residual forming strains from the part geometry itself and assumes that the part was formed from a ...
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Interpretation of Deformation Pattern in Automotive Rails in Frontal Impact
Joseph Hassan, K. Ding, G. Nusholtz - DaimlerChrysler Corp. USA
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Two barriers are commonly used to evaluate the response of a vehicle in a frontal impact: the rigid barrier
and the offset deformable barrier. They produce different deformation patterns, which opens up the possibility that
at least one of them does not represent real world crashes. One possible cause of the difference is that an impact into
a rigid barrier generates significantly greater stress waves than impacts in the real world resulting ...
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eta/VPG: A Virtual Crash and Safety Environment for FMVSS and ECE Standards
Akbar Farahani, Arthur Tang, Tim Palmer, Zubair Uddin - Engineering Technology Associates, Inc.
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Vehicle manufacturers, in an effort to reduce costs and meet the demand of customers are constantly
reducing product development time. At the same time we see more regulations from governments,
primarily aimed at vehicle safety. In additions there are variations in global regulations, such as ECE and
FMVSS regulations.
In order to meet the objective of reducing time and costs, manufacturers are forced to rely more and more
on the virtual ...
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DEVELOPMENT OF A FINITE ELEMENT MODEL OF THE HUMAN BODY
Fuminori Oshita - The Japan Research Institute Ltd.
Kiyoshi Omori, Yuko Nakahira, Kazuo Miki - Toyota Central R&D Labs, Inc.
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A finite element human model, THUMS (Total HUman Model for Safety), was developed in order to study human
body responses to impact loads. This paper briefly describes the structure of the human model, as well as some of
the results of the simulations conducted to validate the model.
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Modular Strategy To Build Full Vehicle Finite Element Mode
Subrato Dhar, William E. Hohnstadt, Jeffrey D. Green - General Motor Corporation
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The modular approach developed is a unique methodology for building a full vehicle finite element model which
allows the use of a single vehicle model, assembled using component modules, to simulate multiple test
configurations. This concept allows multiple users to efficiently contribute to construction of a model that can be
used to run any number of test configurations. The benefits of a modular approach to full-vehicle finite ...
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MULTIDISCIPLINARY DESIGN OPTIMIZATION OF AUTOMOTIVE CRASHWORTHINESS AND NVH USING LS-OPT
K.J. Craig - University of Pretoria
Nielen Stander - Livermore Software Technology Corporation
D.A. Dooge - DaimlerChrysler Corporation
S. Varadappa - Quantum Consultants, Inc.
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This paper describes the multidisciplinary design optimization of a full vehicle to minimize mass
while complying with crashworthiness and Noise, Vibration and Harshness (NVH) constraints.
A full frontal impact is used for the crashworthiness simulation in the nonlinear dynamics code,
LS-DYNA. The NVH constraints are evaluated from an implicit modal analysis of a body-in-
white vehicle model using LS-DYNA. Seven design variables describe the ...
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IMPROVEMENTS TO THE BEVERAGE CAN REDRAW PROCESS USING LSDYNA
Robert E. Dick - Alcoa Technical Center
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In the United States, in the year 2000, over 100 billion aluminum beverage cans were
manufactured. Lightweighting of these aluminum D&I beverage cans has been a continuous
process for more than 35 years. Aluminum beverage can "ends" have been made progressively
smaller over the years in order to reduce costs. Likewise, cost control efforts have resulted in
continuous reduction of the net metal requirements for the can body. To reduce the ...
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PROCESS PARAMETER SENSITIVITY STUDY ON TUBE HYDROFORMING
X.M. Chen - United States Steel Corporation
K. Palanisamy - ETA, Inc.
X.H. Zhu - Livermore Software Technology Corporation
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Finite element analysis (FEA) has proven to be a useful tool for stamping process analyses. FEA has also been used
increasingly for hydroforming analysis in the industry. In this paper, some examples for various hydroforming
process simulations using LS-DYNA are presented. The effects of material characteristics and process parameters
on tubular hydroforming are discussed. A sensitivity study has been conducted on a simple geometry. Three ...
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USE OF MPP-DYNA FOR SIMULATING SHEET METAL FORMING PROCESSES
P. Christopher Galbraith, Dylan N. Thomas - Medusa Computing Corporation
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Sheet forming simulations have been shown to have a profound impact on the tool and die industry, but accurate
solutions for large panels often require large amounts of CPU time. The development of MPP-DYNA has allowed a
large number of CPUs to be applied to a single problem thus reducing total elapsed time. This paper discusses the
use of MPP-DYNA for obtaining accurate solutions in small amounts of elapsed time using inexpensive ...
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ENHANCED FAILURE PREDICTION IN SHEET METAL FORMING SIMULATIONS THROUGH COUPLING OF LS-DYNA AND ALGORITHM CRACH
Gernot Oberhofer, Harry Dell, Dmitri Dell, Helmut Gese - MATFEM
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In sheet-metal-forming the forming limit curve (FLC) is used for ductile sheets to predict fracture in deep drawing.
However the use of the FLC is limited to linear strain paths. The initial FLC cannot be used in a complex nonlinear
strain history of a deep drawing process or a successive stamp and crash process including a significant change in
strain rate. The CRACH software has been developed to predict the forming limit of sheets for ...
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An Optimization Procedure For Springback Compensation Using LS-OPT
Nielen Stander, Mike Burger, Xinhai Zhu, Bradley Maker - Livermore Software Technology Corporation
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The purpose of this study is to develop a methodology for springback compensation in sheet
metal stamping operations. An optimization method is employed to minimize the difference
between the simulation results and the intended design. This procedure results in an optimized
die shape. LS-DYNA, LS-OPT and TrueGrid are used to input original tool geometry, material,
and process parameters, identify design variables, perform springback ...
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Study on Optimal Design of Automotive Body Structure Crashworthiness
Wang Hailiang, Lin Zhongqin, Jin Xianlong - Shanghai Jiao Tong University
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In this paper the optimal model of thin-walled sections of automotive body for structural crashworthiness is built.
With computer design of experiment (DOE), the response surface model (RSM) of design can be obtained by
carefully choosing a small quantity of samples in the design space. Pareto genetic algorithm (GA) is used in
subsequently optimal design. With optimal design of thin-walled sections, the effects of the section parameters ...
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Quasi-Static Finite Element Analysis (FEA) of an Automobile Seat Latch Using LS-DYNA
Song Chen, Yuehui Zhu - Fisher Dynamics Engineering
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In the present automotive industry, all suppliers and OEMs are focusing on designing, developing and
manufacturing products and automobiles with higher quality, lower cost and faster delivery to the customers. The
automobile industry has placed a significant amount of efforts including time and funding into developing products
that can meet these challenges.
This is probably one reason that in recent years Finite Element Analysis (FEA) has ...
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Reduction in Time to Market of Automotive Seating System Using LS-DYNA
Hurshkumar G. Donde, Rakesh K. Lad, Prabal Kumar Biswas, Praveen B. Patil - Infosys Technologies Limited
Gordon Stace - Johnson Control Automotive UK Limited
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The worldwide automotive industry is going through a sea change in order to get the share in the global market,
which is becoming highly competitive & dynamic. The automotive OEM’s are faced with conflicting demands &
challenges. There is an increasing demand for cost & weight reduction, fuel economy & reduction in time to market
on one hand and on the other hand there is even more increasing demand towards assuring improved occupant ...
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Simulation and Validation of FMVSS 207/210 Using LS-DYNA
Vikas Patwardhan, Tuhin Halder, Frank Xu, Babushankar Sambamoorthy - Lear Corporation
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Federal Motor Vehicle Safety Standard 207 and 210 applies to automotive seats, their attachment assemblies, and
seat belt anchorage assemblies. These regulations ensure their proper location for effective occupant restraint, and it
also minimizes the possibility of anchorage failure due to the forces resulting from a vehicle crash.
These requirements are the most critical in seat development process and are generally considered the ...
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Correlation of the Federal Motor Vehicle Safety Standard 225 (FMVSS225) Requirement of an Automotive Seat System Using LS-DYNA
Frank Xu, Partha Chowdhury, Babushankar Sambamoorthy, Tuhin Halder - Lear Corporation
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The National Highway Traffic Safety Administration (NHTSA) has issued a final rule for a new safety standard
related to child seats and their anchorage systems in vehicles. FMVSS 225 – Child Restraint Anchorage Systems
(CRAS) requires that motor vehicle manufacturers provide a new method for installing child restraints that are
standardized and independent of the vehicle seat belt. The requirements for CRAS can ensure their proper ...
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Recent Developments in LS-DYNA for Civil Engineering
Brian Walker - ARUP
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• LS-DYNA has well-known applications for earthquake and
blast/impact engineering
– Building design development
– Site response studies
– Development of isolators and energy absorbers
• Arup have recently added new features:
– Damping model for vibration studies
– Material model - Rock and general Mohr-Coulomb
– Staged construction
– Pore water pressure analysis
• This paper will show some applications of the new ...
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Characterization of Water Impact Splashdown Event of Space Shuttle Solid Rocket Booster Using LS-DYNA
Matthew E. Melis - NASA Glenn Research Center
Khanh Bui - Livermore Software Technology Corporation
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The ALE capability in LS DYNA is used to predict splashdown loads on a proposed replace-
ment/upgrade of the hydrazine tanks on the thrust vector control system housed within the aft
skirt of a Space Shuttle Solid Rocket Booster. Two preliminary studies are preformed in
working towards conducting a full comprehensive analysis: An analysis of the proposed tank
impacting water without supporting structure, and an analysis of actual space ...
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The Future of CAE Software How to Achieve Process Automation
Brian Huf - Ford Motor Company
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Achieving Process Automation is goal of all software – Automatically do what a user needs to get done.
CAE software is no exception. In previous years, technological advances have driven most of the
progress in CAE software. CAE software development is now starting to follow the lead of many other
software companies by leveraging the concept of Process Guidance (a.k.a. Wizards). This approach has
been found to be very effective as well being ...
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Evaluation of the Dropping of a Propeller Shaft During Installation on the USS COLE a DDG 51 Class Destroyer
Phillip Burnside - United States Naval Reserve
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A terrorist bomb damaged the USS COLE by putting a hole in the side of the ship that was over
30 feet in diameter and flooded the forward engine room. After the ship was stabilized it was
placed on the heavy lift ship, the BLUE MARLIN. The BLUE MARLIN brought the
USS COLE back to Ingalls shipyard in Pascagoula, Mississippi for repair as seen in figure 1.
The Navy wanted to expedite the repairs to the USS COLE and so parts from the battle ...
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Non-Penetrating Impact Simulation of Stitched Resin Film Infused Composites
A. M. Floyd, R. Vaziri, A. Poursartip - The University of British Columbia
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The CODAM constitutive model has been implemented in LS-DYNA as a user-defined material model (UMAT).
Using this material model, quasi-static over-height compact tension (OCT) tests on a stitched resin film infused
(S/RFI) carbon/epoxy composite material were simulated, and the results demonstrated good agreement with the
measured force and crack mouth opening displacement (CMOD). The same CODAM inputs were then used to
simulate ...
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Aircraft Engine Blade-Out Dynamics
Kelly S. Carney, Charles Lawrence, Dorothy V. Carney - NASA Glenn Research Center
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A primary problem in the design of aircraft gas turbine engine internal and support structures is the accurate
simulation of the fan blade-out event and the subsequent windmilling of the engine. Reliable simulations of the
blade-out event are required to ensure structural integrity during flight as well as to guarantee successful blade-out
certification testing. A model and procedure has been developed which successfully predicts the key ...
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DROP ANALYSIS OF THE SKID LANDING GEAR OF THE LIGHT HELICOPTER
Alexander V. Konyukhov, Sergey A. Mikhaylov - Kazan State University, Russia
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The analysis of helicopter during landing includes both complicated experimental tests and numerical calculation.
Up to now very simple models in helicopter engineering have been used in Russia. Contemporary investigation of
these problems involves using modern engineering software. The mechanical models included in these software
allow to describe highly nonlinear dynamic behavior of engineering structure. This article contains ...
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Optimum Design of a Cellular Phone Using LS-OPT Considering the Phone Drop Tes
Jung Woo Kim - R & D Center
In-Yong Jo, Young-Gu Chung, Jae Moon Lim - KOSTECH Inc.
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The main factor of the cellular phone fracture is the impact due to the phone drop. Two cases of design criteria are
assigned to reduce the damage of the phone for the drop test. One is that the main part and the battery should not be
separated, being dropped at a height of 30 cm. The other is that they should be separated, being dropped at a height
of 150 cm. The separation between them could reduce the damage of the cellular phone. However, ...
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Materially & Geometrically Nonlinear Woven Composite Micro-mechanical Model with Failure for Finite Element Simulations
Ala Tabiei, Ivelin Ivanov - University of Cincinnati
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A computational micro-mechanical material model of woven fabric composite
material is developed to simulate failure. The material model is based on repeated
unit cell approach. The fiber reorientation is accounted for in the effective
stiffness calculation. Material non-linearity due to the shear stresses in the
impregnated yarns and the matrix material is included in the model. Micro-
mechanical failure criteria determine the stiffness ...
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Incorporation of Material Model into LS-DYNA Implicit to Model the Shear Behavior of Uncured Woven-Fabric Composite Materials
Jennifer L. Gorczyca, James A. Sherwood, Darin S. Lussier, Julie Chen - University of Massachusetts Lowell
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A shear-frame FE model for use in the LS-DYNA implicit code was created to predict the forming behavior of an
uncured woven-fabric composite material. This FE model contains fully integrated shell elements and beam
elements. A material model developed by McBride and Chen for plain-weave woven composite materials and later
refined by Bulusu and Chen to account for different fabric weaves was incorporated into LS-DYNA implicit to
model the ...
