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8th International LS-DYNA Conference

Test and Analysis Correlation of Foam Impact onto Space Shuttle Wing Leading Edge RCC Panel 8
Edwin L. Fasanella - US Army Research Laboratory, Vehicle Technology Directorate, Hampton, VA
Karen H. Lyle - NASA Langley Research Center. Hampton, VA
Jonathan Gabrys - The Boeing Company, Philadelphia, PA
Matthew Melis and Kelly Carney - NASA Glenn Research Center, Cleveland, OH
Soon after the Columbia Accident Investigation Board (CAIB) began their study of the space shuttle Columbia accident, “physics-based” analyses using LS-DYNA were applied to characterize the expected damage to the Reinforced Carbon-Carbon (RCC) leading edge from high-speed foam impacts. Forensic evidence quickly led CAIB investigators to concentrate on the left wing leading edge RCC panels. This paper will concentrate on the test of the ...
The Use of LS-DYNA in the Columbia Accident Investigation and Return to Flight Activities
Jonathan Gabrys, Josh Schatz - The Boeing Company
Kelly Carney, Matthew Melis - NASA Glenn Research Center
Edwin L. Fasanella - US Army Research Laboratory/VTD
Karen H. Lyle - NASA Langley Research Center
During the launch of the Space Shuttle Columbia on January 16, 2003, foam originating from the external tank impacted the shuttle’s left wing 81 seconds after lift-off. Then on February 1st, Space Shuttle Columbia broke- up during re-entry. In the weeks that followed, the Columbia Accident Investigation Board had formed various teams to investigate every aspect of the tragedy. One of these teams was the Impact Analysis Team, which was asked ...
Dynamic FE Analysis of the High-Speed Planetary-Motion Mixer UM-500
Alexey I. Borovkov, Vladimir A. Palmov, Dmitriy S. Mikhaluk, Denis V. Shevchenko - St.Petersburg State Polytechnical University,
In the current paper the results of finite element non-linear mechanical analysis of the energy-saving high-speed planetary-motion mixer UM-500 are presented. The mixer is a system consisting of two milling chambers partly filled with substance to be milled. Milling chambers are in compound motion: rotation about vertical central axis and self-rotation about moving sloping axes. To perform dynamic analysis detailed finite element model is ...
LS-DYNA Implicit for Dent Performance Evaluation
Gagan Tandon, Venugopal Bachu - Altair Engineering Inc.
Present day engineering design involves complex CAE analyses using both linear and non-linear methods. Mos companies use multiple software tools for different types of analyses. Several reasons, including cost are driving companies to investigate lesser number of FEA tools so that they can use a single solver for most of their structural analyses. LS-DYNA has been traditionally used for explicit analysis like crash and metal forming. ...
Numerical Modeling of Woven Carbon Composite Failure
Paul F. Deslauriers, Duane S. Cronin - University of Waterloo
Alex Duquette - Multimatic Technical Centre
This paper presents application of a MLT-based (Matzenmiller, Lubliner, Taylor) approach to model damage in woven carbon composite materials. The MLT formulation has been adapted to shell elements to model individual composite plies. The implementation of the model is discussed along with simple test cases to demonstrate the material response and limitations within the original MLT model. One of these limitations has been addressed through ...
Effect of Triggering Mechanism on the Load-Displacement Response and Folding Pattern of Square Aluminum Tubes
H. El-Hage, N. Zamani - University of Windsor, Canada
P. K. Mallick - University of Michigan-Dearborn, USA
A systematic numerical investigation of the effect of triggering mechanism on the load-displacement characteristics and lobe formation of square aluminum tubes subjected to quasi-static axial compressive load is presented. Among the physical triggering mechanisms considered were chamfering, drilled holes, geometric imperfection and combinations thereof. The effect of corner radius was also considered. This study has shown that the ...
Simulation of Cure Volume Shrinkage Stresses on Carbon/Vinyl Ester Composites in Microindentation Testing
Tom Mase, Lanhong Xu, Lawrence T. Drzal - Michigan State University
Composites made with carbon fibers and vinyl ester have significant higher processing volume shrinkage compared to composites made with epoxies. During the curing, vinyl esters experience as much as three times the volume shrinkage as compared to epoxies (10 %Vol versus 3-4 %Vol). This difference in cure volume shrinkage may be the reason that the mechanical properties of carbon/vinyl esters are low compared to that of carbon/epoxy. ...
Development of an LS-DYNA Model of an ATR42-300 Aircraft for Crash Simulation
Karen E. Jackson, Edwin L. Fasanella - U.S. Army Research Laboratory
This paper describes the development of an LS-DYNA simulation of a vertical drop test of an ATR42-300 twin- turboprop high-wing commuter-class airplane. A 30-ft/s drop test of this aircraft was performed onto a concrete impact surface at the FAA Technical Center on July 30, 2003. The purpose of the test was to evaluate the structural response of a commuter category aircraft when subjected to a severe, but survivable, impact. The aircraft was ...
A Numerical Investigation into HIC and Nij of Children for Forward and Rearward Facing Configurations in a Child Restraint System
William Altenhof, Rita Turchi - University of Windsor
This study explores the various differences in potential for injury in 3-year-old children in the case of a frontal collision. A crash analysis between forward and rearward facing children, both restrained in a five-point child restraint, was performed using numerical simulation methods. This comparison was carried out by conducting numerical simulations of these situations using the criteria outlined in FMVSS 213. The injuries that were ...
FEM for Impact Energy Absorption with Safety Plastic
Iulian Lupea, Joel Cormier, Sital Shah - The Oakwood Group
For the engineering design process to benefit from finite element modeling (FEM), it must adequately represent any condition being studied. This paper presents methodologies for using the LS-DYNA non-linear finite element solver to model a patented energy absorbing technology called SafetyPlastic®. SafetyPlastic® offers a performance, cost, and mass competitive energy management solution, and has been embraced by the automotive industry in ...
Implementation of Modal Representation for Full Vehicle VPG Simulations
Xianggang Zhang - Engineering Technology Associates, Inc.
The modal representation method matured in LS-DYNA 970. It is a useful tool for full vehicle, long duration Virtual Proving Ground (VPG) analyses. The CPU time for VPG analysis could be dramatically reduced with such application. Modal representation method uses linear combination of the pre-calculated mode shapes to represent portion of the full vehicle model in transient dynamic analysis. The linear modal response of this portion of ...
IIHS Side Impact Analysis Using LS-DYNA/Madymo Coupling
Jiri Kral - TNO Madymo North America
Prabhu Setru, Swarna Rajeswaran - General Motors
The LS-DYNA/Madymo coupling has a growing popularity in the field of vehicle crash analysis as it allows the users to merge an existing occupant simulation subsystem model and a full car structural model into one system. The extended coupling feature introduced in late 2002 has significantly enhanced this model fusion capability. This paper demonstrates the application of such a coupling technique for the simulation of the IIHS ...
Influence of Pre-Stressed Parts in Dummy Modeling - Simple Considerations
Ulrich Franz, Peter Schuster, Sebastian Stahlschmidt - DYNAmore GmbH
New regulations and consumer tests for passive safety in passenger cars have increased the de- mand on accurate models for occupant analysis. Thus, effects that have been neglected or mod- eled rather coarsely in recent occupant models might necessitate a more detailed modeling in order to capture the dummy behavior sufficiently accurate. This paper contributes to the discussion of the importance and the modeling techniques of pre- stressed ...
A FE Modeling and Validation of Vehicle Rubber Mount Preloading and Impact Response
Sae U. Park, Madhu R. Koka, Kevin R. Thomson, Jeffrey L. Robbins - DaimlerChrysler Corporation
A variety of rubber mounts are being used for vehicles as isolators/dampers between body and frame, on the engine cradle, etc. It has been the prevalent CAE practice in the auto industry to evaluate the mounts’ high-speed vehicle crash response by the means of nonlinear spring/beam models. However, the simplified models carry a risk of generating incomplete and erroneous results, especially under very complex crash loadings due to the absence ...
A Benchmark Study of CAE Sensor Modeling Using LS-DYNA
C. C. Chou, P. Chen, J. Le - Passive Safety R&A, Ford Motor Company
Nasser Tamini - ETA
This paper presents results from a benchmark study of CAE sensor modeling using LS-DYNA. Using the VPG translator, a sensor model was converted from a calibrated RADIOSS model into LS-DYNA input formats for frontal impact simulations carried out in this study. Since two codes have different material laws, element library and functionalities, those deemed to be as closed to RADIOSS were chosen in the translation process. For those that could ...
Study of a Driver Airbag Out-Of-Position Using ALE Coupling
Wenyu Lian - General Motors
Dilip Bhalsod - Livermore Software Technology Corporation
The new FMVSS 208 regulation specifies the airbag performances under Out-of-Position conditions. During the past 10 years, the thermodynamic-based airbag models have been successfully used in analyzing the occupant interaction with the airbag under regular crash conditions (in-position). However, these models are not suitable for the airbag OOP applications since they can not accurately predict the flow forces that dominate the ...
An Investigation of Structural Optimization in Crashworthiness Design Using a Stochastic Approach
Larsgunnar Nilsson, Marcus Redhe - Engineering Research Nordic AB, Sweden
In this paper the Response Surface Methodology (RSM) and the Stochastic Optimization (SO) are compared with regard to their efficiency and applicability in crashworthiness design. Optimization of simple analytic expressions and optimization of a front rail structure are application used in order to assess the respective qualities of both methods. A low detailed vehicle structure is optimized to demonstrate the applicability of the methods in ...
Robustness Study of an LS-DYNA Occupant Simulation Model at DaimlerChrysler Commercial Vehicles Using LS-OPT
Dr. Frank C. Günther - DaimlerChrysler
Dr. Heiner Müllerschön, - DYNAmore GmbH
Dr. Willem Roux - Livermore Software Technology Corporation
The robustness properties of crash simulation models are emerging as an important criterion in today's simulation driven vehicle development process. We consider it relevant to any study of highly non-linear crash problems to obtain measures for the repeatability and reliability of both experimental and numerical tests. In 2003, we conducted a robustness study of a structural front impact model (JAPAN LS-DYNA Users Conference 2003) using ...
Horizontal Tailplane Subjected to Impact Loading
M. Hörmann, U. Stelzmann - CAD-FEM GmbH, Germany
M.A. McCarthy - University of Limerick, Ireland
J.R. Xiaoc - University of Delaware, USA
The European Union Research Programme CRAHVI (CRashworthiness of Aircraft for High Velocity Impact) is concerned with the high velocity impact of aircraft due to flying objects, e.g. bird, hailstone, tyre and engine debris as well as concerned with survivable crash landings on different surfaces, e.g. rigid inclined surfaces (slopes) and water with different sea states. The simulation is naturaly a complex task due to the high number of ...
Crashworthiness Design of Vehicle Structures via Equivalent Mechanism Approximations
Karim Hamza, Kazuhiro Saitou - University of Michigan
A new method for crashworthiness optimization of vehicle structures is presented. In the new method, early design exploration is done by the optimization of an equivalent mechanism approximating a vehicle structure. An equivalent mechanism (EM) is a network of rigid bodies connected by prismatic and revolute joints with special nonlinear springs. These springs are tuned to mimic the force-displacement characteristics of thin-walled ...
LS-OPT Capabilities for Robust Design
Nielen Stander, Willem Roux - Livermore Software Technology Corporation
This paper presents a number of new features available in LS-OPT Version 2.2. As a step toward robust design, the code has been extended to enable reliability assessment and the identification of sources of unpredictability in the FE model. In the latter feature, deterministic and stochastic effects can be separated.
ALE and Fluid Structure Interaction in LS-DYNA
M. Souli - Laboratoire de Mécanique de Lille
J. Wang, I. Do, C. Hao - Livermore Software Technology Corporation
Fluid-structure interactions play an important role in many different types of real-world situations and industrial applications involving large structural deformation and material or geometric nonlinearities. Numerical problems due to element distortions limit the applicability of a Lagrangian description of motion when modeling large deformation processes. An alternative technique is the multi-material Eulerian formulation for which ...
Simulation and Verification of the Drop Test of 3C Products
Hsing-Ling Wang - Chinese Air Force Academy
Shia-Chung Chen, Lei-Ti Huang, Ying Chieh Wang - Chung-Yuan Christian University
Drop test performance has become one of the most crucial evaluations for Computer, Communication, and Consumer (3C) products. Both simulation tool and practical platform for drop test must be established for detailed study. A patented drop test platform is designed for the purpose of impact angle repeatability and instantaneous drop image capture at impact instance. These parameters are two crucial computer-aid-engineering (CAE) inputs ...
Drop Simulation for Portable Electronic Products
Raymon Ju, Brian Hsiao - Flotrend Co., Taiwan
The portable electronic devices are becoming smaller and lighter in recent years, and hence these products are easily damaged under the drop and impact conditions. Traditionally, manufacturers must have lots of mockups and samples to simulate the impact behavior through experiment. To minimize the development period and the try-and- error costs, ODMs in Taiwan begin to predict the impact behavior by LS-DYNA. For ODMs who want to ...
Moving Beyond the Finite Elements, a Comparison Between the Finite Element Methods and Meshless Methods for a Ballistic Impact Simulation
Murat Buyuk, Cing-Dao Steve Kan, Nabih E. Bedewi - The George Washington University
Ali Durmus, Sedat Ulku - Uludag University
For the past several decades, finite element techniques have been used extensively for the analysis of computational solid mechanics problems. However, when the distortions become very severe, especially Lagrangian finite element algorithms are not always adequate. More recently meshless methods (or particle methods) have been developed and applied to solid mechanics problems since they can efficiently be used to represent severe distortions ...
Simulation of Energy Absorbing Materials in Blast Loaded Structures
Michael J. Mullin, Brendan J. O’Toole - University Nevada Las Vegas
Energy absorbing materials such as foam or honeycomb are of interest in blast protection because of their ability to absorb energy through plastic deformation. After reaching their yield stress, these materials exhibit a region of constant stress for increasing strain until the material is completely compacted. The energy needed to crush the material is proportional to the area under the stress-strain curve. Because foams and honeycombs ...
Explosive Welding of Light Weight Metal Sheets
Yamato MATSUI , Masahiko OTSUKA, Takeshi HINATA, Shigeru ITOH - Kumamoto University
Erik CARTON - TNO-Prins Maurits Laboratory
The technique of explosive line welding is one of the processing techniques and it can connect similar and dissimilar metal sheets using large energy of explosive during very short time. In this study we try to weld lightweight metal sheets by experiment and work on the numerical simulation concerning a series of the phenomenon. Materials involved are aluminum alloys Al5052-O, 6061T6 and 6M83, magnesium alloy AZ31B-O and commercially pure ...
Effects of Pre-Pressurization on Plastic Deformation of Blast-Loaded Square Aluminum Plates
R.L. Veldman, C. Clum, J. Folkert - Hope College
J. Ari-Gur - Western Michigan University
The effects of static pre-pressurization on the blast-induced deformation of square aluminum plates were studied both experimentally and numerically. In this study, small (0.152 x 0.152 x 0.0016 meter) clamped plates were used as a basic model of the fuselage skin of a commercial aircraft. Both un-pressurized and pre-pressurized plates (static pressure of 62.1 KPa (9.0 psi)) were considered to simulate the minimum and maximum in-flight ...
Transient Response of a Projectile in Gun Launch Simulation Using Lagrangian and ALE Methods
Ala Tabiei - University of Cincinnati
Mostafiz R. Chowdhury - U.S. Army Research Laboratory
This paper describes the usefulness of Lagrangian and arbitrary Lagrangian/Eulerian (ALE) methods in simulating the gun launch dynamics of a generic artillery component subjected to launch simulation in an air gun test. Lagrangian and ALE methods are used to simulate the impact mitigation environment in which the kinetic energy of a projectile is absorbed by the crushing of an aluminum honeycomb mitigator. Issues related to the effectiveness ...
Energy Absorbing Sandwich Structures Under Blast Loading
Dong Kwan (David) Lee, Brendan J. O’Toole - University of Nevada, Las Vegas
A recent experimental study at the Army Research Laboratories shows that flat panels with various foam or honeycomb faceplates transferred more energy to a structure under blast loading relative to a structure without an energy absorbing faceplate. Ideally, the foam or honeycomb material should transfer less energy to the structure since it absorbs energy while it deforms plastically. Non-uniform deformation of the energy absorbing material ...
Preliminary Assessment of Non-Lagrangian Methods for Penetration Simulation
Leonard E. Schwer - Schwer Engineering and Consulting Services
Lagrangian, Eulerian, and Smooth Particle Hydrodynamics formulations are applied to the simulation of a rigid fragment impacting a concrete panel. An effort is made to keep much of the computational model constant across the simulations. All three methods are shown to be appropriate for this class of ballistic impact simulation. The results and conclusions are preliminary, but the paper serves as an introduction to these alternative forms ...
Curved Barrier Impact of a NASCAR Series Stock Car
Eric A. Nelson, Li Hong - Altair Engineering
A detailed finite element model of a NASCAR Series stock car has been developed by Altair Engineering and used to study a curved barrier impact. This paper will review some of NASCAR’s capabilities in the area of motor sports safety research and provide an overview of a study that has been performed by Altair Engineering. Specifically, the author will compare and contrast results from a curved barrier impact in 3 different scenarios: ...
Development of a Hybrid Energy Absorbing Reusable Terminal (HEART) Using Finite Element Modeling in LS-DYNA for Roadside Safety Applications
Nauman M. Sheikh, Dean C. Alberson, D. Lance Bullard - Texas Transportation Institute
The Hybrid Energy Absorbing Reusable Terminal (HEART) is a newly developed crash cushion or an end terminal to be used in highway safety applications that will mitigate injuries to occupants of errant vehicles. The HEART is composed of corrugated plates of High Molecular Weight/High-Density Polyethylene (HMW/HDPE), supported on steel diaphragms, which slide on a fixed rail. Kinetic energy from errant vehicles is converted to other energy ...
An Evaluation of Active Knee Bolsters
Zane Z. Yang - Delphi Corporation
In the present paper, the impact between an active knee bolster system and occupant knees has been studied using finite element analysis. The active knee bolster system consisted of an inflatable molding part and a pair of EA supporting brackets. Also included in the FEA model was the entire vehicle cockpit. Both driver-side and passenger- side occupants were considered. The active knee bolster FEA model was first validated by test data ...
Strain Rates in Crashworthiness
Moisey B. Shkolnikov
Strain rates related tests, strain rates measurements, strain rates states during vehicle collisions, crashworthiness tests and simulations are discussed in the paper. Several papers (on which some of LS-DYNA strain rates options in constitutive models for metals are based) are considered in this paper from an automotive vehicle crashworthiness point of view. Strain rates effect on structure’s metals during explosions are mathematically ...
Prediction of Seat Deformation in Rear Crash Using LS-DYNA
Biswanath Nandi, Dinesh Jain - Lear Corporation, USA
It has always been a challenging task to simulate occupied rear crash for seating system. To design an ideal seat for resisting the load during rear impact is also a difficult task for the seat suppliers. Seat Suppliers are in continuous search of newer methods and techniques to reduce number of prototypes and testing cost. Analytical methods of predicting structural behavior using computer aided engineering (CAE) has been in place for quite ...
A New Concept on Stamping Die Surface Compensation
Li Zhang, Jin Wu, Dajun Zhou - DaimlerChrysler Corporation
XinHai Zhu - Livermore Software Technology Corporation
This paper classifies existing die compensation methods into two general categories, geometry-based method and springforward method. To meet the challenge of increased application of AHSS and its associated severe springback problems, we propose a new concept by using the tooling mesh of design intent as reference during compensation iterations. Incorporation of this concept into these two original methods enhances the efficiency and accuracy ...
The Dynamic Problems in High Speed Transfer Stamping System
Ming-Chang Yang, Hsing-Chih Tsai and Tien-Chi Tsai - Metal Industries Research and Development Centre
In this paper the authors would like to disclose the application of LS-DYNA, the dynamic explicit finite element method, in high speed transfer stamping system development. Transfer stamping process has the advantages of material saving and automation especially for stamping parts with complicated geometry. The dynamic effects will be induced as the stamping speed up to 200 SPM i.e. the contact dynamics of barrel cam and followers, ...
Application of FEA in Stamping Auto Underbody Parts
Yuyuan Wang, Marcel Pillon, Ron Ouellette, Chris Pitre, John Laporte - Canadian Engineering and Tool
The complex auto underbody components need a long process of die design and tryout, some times need several to hundred times of costly trial-and-error to get required stamping parts. It is very critical to the die design how to decide and evaluate the die shapes of each forming stage and how to distribute the deformations between preform(s) and form for multi-stage forming. Combination of simulations for each forming stage using Dynaform and ...
Through Process Modelling of Self-Piercing Riveting
R. Porcaro, A.G. Hanssen, M. Langseth, A. Aalberg - Norwegian University of Science and Technology
Self-piercing riveting is a relatively new process for joining sheet metals in automotive structures. Information obtained from the riveting process simulation can lead to an improvement in the process design achieving reduction in cost and improvement in the quality of the joint. The process data can also be used to set initial parameters for a 3D simulation of the self-piercing rivet connection under combined tensile and shear loading ...
Numerical Simulation of Aluminum Alloy Forming Using Underwater Shock Wave
Hirofumi Iyama - Yatsushiro National College of Technology
Kousei Takahashi - Kumamoto Industrial Research Institute
Takeshi Hinata, Shigeru Itoh - Kumamoto University
In recent years, on automobile industry, the car has body using aluminum alloy. As for this material, #5000’s, 6000’s and 7000’s aluminum alloy is used well. However, the sheet metal forming of these materials by the static method, such as the hydro bulge forming and general punching, is very difficult, because these are little elongation compared with major steel. We considered application of the explosive forming. Therefore, we have tried ...
Finite Element Modeling of Material Damage in Axially- Loaded Aluminum Tubes with Circular Hole Discontinuities
Bryan Arnold, William Altenhof - University of Windsor
Finite element simulations of the axial crushing of extruded aluminum tube structures were conducted using LS-DYNA in order to investigate their load management and energy absorption characteristics. The structures under consideration were made from aluminum alloy 6063-T5 and contained dual centrally located circular hole discontinuities. The results of the finite element simulations are compared to the results of quasi-static experimental ...