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7th European LS-DYNA Conference

New Features in LS-DYNA EFG Method for Solids and Structures Analysis
C. T. Wu - LSTC
In this presentation, an update on LS-DYAN EFG method for solids and structures analysis will be given. Several features were developed in the past two years to solve specific challenging problems as well as to improve the efficiency. This talk will emphasize on three new features including an adaptive Meshfree scheme based on a local Maximum Entropy approximation for metal forging and extrusion analysis, a semi-Lagrangain formulation in ...
SPH Formulations: New Developments in LS-DYNA
J. L. Lacome - Livermore Software Technology Corp
“Standard” SPH methods are based on an Eulerian kernel. In most cases, the support remains constant and the neighbors search is carried out at each time step. This allows to deal with large deformation problems. However, this technique may suffer from instabilities (such as the so-called tensile instability [Xiao 05]). In the case of a Lagrangian kernel, the neighbors’ list remains constant throughout the calculation. This formulation ...
ALE Formulation for the Evaluation of Seismic Behaviour of Anchored and Unanchored Tanks
Z. Ozdemir - Bogazici University / Université de Lille
M. Souli - Université de Lille
Y. Fahjan - Gebze Institute of Technology
Estimation of the potential degree of risk for tank failure during an earthquake is very difficult to quantify since the liquid-tank system possesses many different nonlinear behaviour mechanisms which may be triggered simultaneously or separately depending on the characteristics of earthquake, contained liquid properties, fluid depth, dimensions of the tank, roof type, material properties, supporting conditions and stiffness of underlying ...
ALUMINUM PLATE PERFORATION: A COMPARATIVE CASE STUDY USING LAGRANGE with EROSION, MULTI-MATERIAL ALE, and SMOOTH PARTICLE HYDRODYNAMICS
Leonard E Schwer - Schwer Engineering & Consulting Services
The focus of the present work is to perform an assessment of a relatively new class of numerical methods, referred to as meshfree methods, that offer analysts an alternate analytical technique for simulating this class of ballistic problems, without a priori trajectory knowledge, nor resorting to ad hoc criteria. The assessment is made by the comparison of projectile residual speeds provided by the various techniques, when used to simulate a ...
Numerical Simulation of the Critical Blast Wave of Mines on APV's Crew Members
Alon Brill - Netvision
Paul A. Du Bois - Consulting Engineer
Blast wave generated by energy released when a mine is detonated, travels through the air at supersonic velocity. Has a high pressure front and hits a vehicle in about 100 μm giving rise to overpressure on it. Blast created by expanding explosion products and air moving behind shock front; results in dynamic pressure on a vehicle. Soil ejecta thrown up when mines are buried in the ground; augment significantly impact of blast ...
A Coupling of Empirical Explosive Blast Loads to ALE Air Domains in LS-DYNA
Todd P. Slavik - Livermore Software Technology Corporation
A coupling method recently implemented in LS-DYNA® allows empirical explosive blast loads to be applied to air domains treated with the multi-material arbitrary Lagrangian-Eulerian (ALE) formulation. Previously, when simulating structures subjected to blast loads, two methods of analysis were available: a purely Lagrangian approach or one involving the ALE and Lagrangian formulations coupled with a fluid-structure interaction (FSI) ...
Developing Failure Criteria for Application to Ship Structures Subjected To Explosive Blast Loadings
Mark Tyler-Street, Joke Luyten - TNO Defence
A research programme is being undertaken at TNO to investigate vulnerability reduction on warships. In this framework, studies have been performed regarding the structural damage due to both an internal missile explosion and close in explosions. Due to the severity of the explosive loadings the structural deformation is considerable and an accurate method to predict both the initiation and progression of material damage would be ...
Modelling of the dynamics of a 40 mm gun and ammunition system during firing
N. Eches, D.Cosson - Nexter Munitions
Q. Lambert - C.T.A. International
A. Langlet - C.T.A. International / Université d’Orléans
J. Renard - Université d’Orléans
This paper deals with the development of a finite element model of a 40 mm Case Telescoped Ammunition and its associated gun, able to describe the in-bore travel of the projectile during firing. This work is part of a PhD thesis, supervised by CTA International and the PRISME Institute, dedicated to the study of the parameters relevant to the accuracy of the Kinetic Energy Round. In order to conduct efficient parametric studies, they asked ...
Crash and Vibration Analysis of rotors in a Roots Vacuum Booster
Manuel Roth - Pfeiffer Vacuum GmbH
Stefan Kolling - Giessen University of Applied Sciences
The dynamic behaviour of a roots vacuum booster with two rotors is presented. The dynamic response of the structure is, thereby, investigated using an explicit analysis for the crash behaviour and an implicit analysis for the vibration behaviour. Typically the rotors run from 3000rpm to 3600rpm, but because of a desired rise in power density it is necessary to design rotors for operation at 6000rpm. With increasing rotational velocity the ...
Experimental and Simulation Characterization of the Suspension of a Small Car
W. Tiu - University Hertfordshire
This paper will describe the work carried out to compare the experimental response of the car using a four actuator vibration rig and that obtained from an LS-dyna analysis using the same loading spectrum as that used in the physical experiment. The public domain frontal crash FE model was modified to reduce the solution time. Most of the materials used in the panels were changed to rigid as these were not expected to deform during a ...
Development of a Software for the Comparison of Curves During the Verification and Validation of Numerical Models
Mario Mongiardini, Malcolm H. Ray - Worcester Polytechnic Institute,
Marco Anghileri - Politecnico di Milano
This paper describes the development of the Roadside Safety Verification and Validation Program (RSVVP), a software that automatically assesses the similarities and differences between two curves. This program was developed to assist engineers and analysts in performing curve comparison during the verification and validation process of a numerical model. RSVVP was designed to automatically preprocess the two input curves to make them ...
Comparison of crash tests and simulations for various vehicle restraint systems
M. Massenzio, S. Ronel - Université de Lyon
C. Goubel - Université de Lyon / Laboratoire INRETS Equipements de la Route (LIER SA), Lyon Saint Exupéry Aéroport
E. Di Pasquale - SIMTECH
The use of computational mechanics methods is now largely adopted in the field of Road Side Safety. They are certainly interesting in the context a product development. However, the application of these methods in the certification process raises number of issues, addressed, among others, within the EU CEN TC226/WG1/TG1/CM-E, where some of the authors participate. This paper presents some crash test results and their related simulations, and ...
Simulation of a clamping ring under high dynamic loading
S. Edelmann, C. Groß, H. Chladek - INPROSIM GmbH
Clamping rings are used in a wide range of mechanical applications in order to assemble two or more cylindrical parts, e.g. tubes and pipes, pressure vessels and tanks. Another application area of clamping rings is in turbo engines, where they connect compressor, bearing and turbine casings for example. For normal operating conditions, standard rules or simple static analyses are adequate to determine the relevant design parameters of this ...
Verification of cylindrical interference fits under impact loads with LS-Dyna
Prof. Dr.-Ing. Helmut Behler, Jan Göbel, M.Eng. - Hochschule Mannheim
Steffen Heute, M.Eng. - Alpha Engineering Services GmbH
Interference fits are a commonly used means to couple shafts and wheels for example. The usual dimensioning is performed by a static verification. As long as the system geometry is not too complicated and the deformation is assumed to be linear elastic, the interference pressure can easily be calculated with the more familiar solutions of the equations of elasticity. The maximum static contact forces can be calculated together with an ...
Drop Test Analysis of a Lamy Pencil
Dr.-Ing Matthias Hörmann, Steffen Schiele - CADFEM GmbH
Reinhard Probol - LAMY GmbH
Consumer products like cell phones, personal digital assistants, dish washers or cookers, to name just a view of them, are often exposed to drop during transportation to the customer and during usage in life time. Pre-damage, failure or malfunction due to drop is typically not acceptable and will lead to refusal through the costumer in addition with a correspondingly amount of financial and prestige loss. The present work deals with the ...
Finite element modeling of the ITER superconducting cables mechanical behaviour using LS-DYNA code
A.S. Nemov , A.I. Borovkov - St.Petersburg State Polytechnical University
B.A. Schrefler - University of Padua
Superconducting cables are one of the key technical solutions used for generation of strong magnetic field in modern tokamaks. It is very important for engineers to be able to predict the mechanical deformations of superconducting cables because superconductivity depends on strains, temperature and magnetic field. Superconducting cables for ITER the International Thermonuclear Experimental Reactor [1] currently under construction, ...
High-Mass, Low-Velocity Impacts on Reinforced Concrete Slabs
A. J. Sangi, I. M. May- Heriot-Watt University Edinburgh
The behaviour of reinforced concrete in quasi static regimes has been investigated extensively but there have been few investigations into its transient behaviour, especially under low velocity regimes. This paper describes the finite element modelling and analysis of reinforced concrete slabs under drop-weight impact loads using LS-DYNA. The results obtained from the numerical simulations have been compared with tests that were carried out ...
An LS-DYNA material model for simulations of hot stamping processes of ultra high strength steels
Dr. Tobias Olsson - Engineering Research Nordic AB
This paper present a new material model (*MAT_244) in LS-DYNA capable of simulating phase transition during quenching and forming. Usually during forming the blank is initially heated to become fully austenitized and then continuously formed and cooled. When the temperature is decreasing the austenite decomposes into different product phases. The amount of each phase does not only depend on the mechanical history, but also on the cooling ...
Modelling the dynamic magneto-thermomechanical behaviour of materials using a multi-phase EOS.
Le Blanc Gaël, Jacques Petit, Pierre-Yves Chanal - Centre d’Etudes de Gramat
L’Eplattenier Pierre - LSTC, Livermore
Avrillaud Gilles - ITHPP
For several years the “Centre d’Etudes de Gramat (CEG)” has been studying the behaviour of materials by means of experimental devices using High Pulsed Powers technologies. Among them, GEPI is a pulsed power generator devoted to ramp wave (quasi isentropic) compression experiment in the 1 GPa to 100 GPa pressure range. It may also produce non shocked high velocity flyer plates in the 0.1 km/s to 10 km/s range of velocity. The basic principle ...
Adjusting the Contact Surface of Forming Tools in Order to Compensate for Elastic Deformations during the Process
Knut Großmann, Hajo Wiemer, Andrè Hardtmann, Lars Penter, Sebastian Kriechenbauer - TU Dresden
Nowadays, despite powerful simulation programs, the tool design process still contains manual and not reproducible work. In specific, the manual die spotting is mostly dependent on the workers experience and consumes a lot of time. A large potential to reduce time and costs is seen by decreasing the die maturing. The paper introduces an approach to obtain deep drawing tools from FE simulation with LS-DYNA, which need less additional manual ...
Improved Tool development Process for novel SCS Technology for Aluminium Sheet Metal
Apostolos Papaioanu, Prof. Dr. Mathias Liewald MBA - Institut für Umformtechnik, Stuttgart
Ralf Schleich - HochschulInstitute Neckarsulm, Neckarsulm
Today’s stretch forming technologies mainly are used for production of large and flat parts made of sheet metal mainly for the aircraft industry (wing fabrication) and for shipbuilding. Because of the high investment costs and high process time, the use of such conventional stretch forming technologies is not qualified for production of car body panels. However, benefits of present stretch forming methods such as improvement of the ...
A PARAMETRIC AND USERFRIENDLY APPROACH TO INCREMENTAL PROCESS SIMULATION OF SHEET METAL FORMING
Dr. Victor Apanovitch, Stefan Huhn - Forming Technologies Inc.
With a steady increase in computational power and decrease in hardware costs during the last few years, the incremental process simulation in the area of sheet metal forming is considered a state-of- the-art tool during the development process at OEMs and many, mainly larger, suppliers. However, the existing pre-processing tools do not support a template based analysis setup that can prevent the need for highly skilled personnel in order to ...
A numerical study of the effect of geometrical factors on bi-layered tube hydroforming
Abed Alaswad, Abdul Ghani Olabi - Dublin City University
Tube hydroforming is one type of unconventional metal forming process in which high fluid pressure and axial feed are used to deform a tube blank in the desired shape. Bi-layered tube hydroforming is suitable to produce bi-layered joints which can be used in special applications such as aerospace, oil production, and nuclear power plants. In this work a finite element study was performed using ANSYS LS-DYNA to investigate the effect ...
Modelling of ductile failure in metal forming
H.H. Wisselink, J. Huetink - Materials Innovation Institute (M2i) / University of Twente
Damage and fracture are important criteria in the design of products and processes. Damage mod- els can be used to predict ductile failure in metal forming processes. Nonlocal models avoid the mesh dependency problems of local damage models. A nonlocal damage model has been implemented in LS- DYNA using the user-subroutines UMAT and UCTRL1. The implemented model will be compared with results obtained with the available option in LS-DYNA to ...
Numerical investigation of draw bending and deep drawing taking into account cross hardening
Clemens Barthel, Till Clausmeyer, Bob, Svendsen - University of Technology,Dortmund, Germany
Sheet metal forming is one of the most important manufacturing processes. Computer simulation has become the tool for modeling such processes and also for predicting the springback in the final part. The talk will deal with two different metal forming processes, namely draw bending and deep drawing of a cup. In the draw bending case a metal strip is clamped into a testing device in such a way that it is bent over a roller. The strip is then ...
Identification of an advanced hardening model for single phase steels
Muhammad Noman, Bob Svendsen - University of Dortmund
Sheet metal forming processes cover a wide range of applications in industry. In order to model sheet metal forming processes using numerical simulation an accurate description of the material behavior is required. To this end a material model has been implemented which is capable of capturing the move- ment and proportional expansion of the yield surface along with the change in the shape of the yield surface. The former is described as ...
Forming limit diagrams with an FE-based approach for sheets under non-proportional loading
A. Reyes, O. S. Hopperstad - Norwegian University of Science and Technology
T. Berstad, O.-G. Lademo - Norwegian University of Science and Technology/ SINTEF Materials and Chemistry
In this study, LS-DYNA was used to predict the experimental forming limit diagrams (FLDs) for pre- strained sheets in aluminum alloy Al2008-T4 found by Graf and Hosford [1]. The original data of Graf and Hosford [1] includes numerous pre-straining situations, but it was here chosen only to investigate pre-straining by biaxial and uniaxial tension. In order to generate the FLDs, several analyses of a square patch were run systematically to ...
A Systematic Approach to Model Metals, Compact Polymers and Structural Foams in Crash Simulations with a Modular User Material
G. Oberhofer, H. Gese - MATFEM Partnerschaft Dr. Gese & Oberhofer
A. Bach, M. Franzen, H. Lanzerath - Ford Research & Advanced Engineering Europe
Today the automotive industry is faced with the demand to build light fuel-efficient vehicles while optimizing its crashworthiness and stiffness. A wide variety of new metallic and polymeric materials have been introduced to account for these increased requirements. Numerical analysis can significantly support this process if the analysis is really predictive. Within the numerical model a correct characterization of the material behaviour – ...
Micromechanics analysis applied to the modelling of aluminium honeycomb and EPS foam composites
Gaetano Caserta, Lorenzo Iannucci - Imperial College London
Ugo Galvanetto - Padova University
A 3D Finite Element model of an innovative composite material, configured as a layer of expanded aluminium honeycomb placed on top of a layer of expanded polystyrene foam, has been developed and validated against experimental data obtained from quasi-static tests. Ls-Prepost was used to generate the model. Ls-Dyna was used to simulate the behaviour of this material under compressive loads. The objective was to reproduce deformation ...
Behaviour and Modelling of Dual-Phase Steels
Venkatapathi Tarigopula, Odd Sture Hopperstad, Magnus Langseth, Arild Holm Clausen - Norwegian University of Science and Technology (NTNU)
Dual-phase steels are being increasingly considered for application in vehicle structural crash components because of their combined attributes of high-strength and good formability characteristics. Accurate prediction of such components, which are often made of formed components, is necessary to reduce the cost of physical tests. The non-linear finite element method is an efficient and reliable tool for the design of new components. The ...
Multi-Scale Modeling of Crash & Failure of Reinforced Plastics Parts with DIGIMAT to LS-DYNA interface
L. Adam, A. Depouhon, R. Assaker - e-Xstream engineering
This paper deals with the prediction of the overall behavior of polymer matrix composites and structures, based on mean-field homogenization. We present the basis of the mean-field homogenization incremental formulation and illustrate the method through the analysis of the impact properties of fiber reinforced structures. The present formulation is part of the DIGIMAT [1] software, and its interface to LS-DYNA, enabling multi-scale FE ...
Numerical simulation of low-velocity impact loading of polymeric materials
H. Daiyan, F. Grytten, E. Andreassen, R.H. Gaarder, E.L. Hinrichsen - SINTEF Materials and Chemistry
O.V. Lyngstad - Plastal AS
H. Osnes - University of Oslo / Simula Research Laboratory
Simulation of ductile polymers subjected to impact loading has become an important topic [1, 2], especially for automotive components related to passenger and pedestrian safety. The aim of our work is to establish and validate numerical models for impact response, and this presentation will focus on a study of impact on injection molded polypropylene plates. SAMP-1 (Semi-Analytical Model for Polymers) [3] was selected as constitutive model ...
A constitutive model for thermoplastics intended for structural applications
Mario Polanco-Loria, Torodd Berstad - SINTEF Materials and Chemistry / Structural Impact Laboratory (SIMLab)
Arild Holm Clausen, Odd Sture Hopperstad - Department of Structural Engineering, NTNU/Structural Impact Laboratory (SIMLab)
This paper presents a hyperelastic-viscoplastic constitutive model for thermoplastics [1]. It is partly based on a model proposed by Boyce et al. [2]. The model involves a hyperelastic- viscoplastic response due to intermolecular resistance, and an entropic hyperelastic response due to re-orientation of molecular chains. A Neo-Hookean material model is selected for describing large elastic deformations. Moreover, the Raghava plastic yield ...
Selecting Material Models for the Simulation of Foams in LS-DYNA
Brian Croop,Hubert Lobo - DatapointLabs
Foams are multi-phase materials that exhibit dramatically different properties that depend on the matrix material as well as the pore microstructure. This additional degree of freedom from the presence of the gas phase makes material modelling for foams a difficult matter. LS-DYNA offers a variety of material models, each with capabilities designed to capture the unique behaviour of a different types of foam. The selection of the correct ...
Simulation of Dynamic Delamination and Mode IEnergy Dissipation
Muhammad Ilyas, Christine Espinosa, Frédéric Lachaud, Michel Salaün - Université de Toulouse
Delamination initiation and propagation of aeronautic composites is an active field of research. In this paper we present a methodology for critical energy release rate correlation of numerical simulation and experimental data. Experiments of mode I critical energy release rate were carried out at quasi static and pseudo dynamic loading rates. Cohesive finite elements are used to predict the propagation of delamination in a carbon fiber and ...
A Study of Material and Architectural Effects on the Impact Response of 2D and 3D Dry Textile Composites using LS-DYNA
Gaurav Nilakantan, Michael Keefe, John W. Gillespie Jr. - University of Delaware
Travis A. Bogetti, Rob Adkinson - US Army Research Laboratory
High strength 2D fabrics and 3D textile composites comprised of materials such as KevlarTM, VectranTM, ZylonTM, and S2-Glass® find applications in protective systems such as personnel armor, spall liners, and turbine fragment containment. Various parameters can significantly affect the response of these fabrics under high rate impact including yarn/tow geometry (cross section), yarn/tow material (modulus, strength), and architecture ...
Taking into Account Glass Fibre Reinforcement in Polymer Materials: the Non Linear Description of Anisotropic Composites via the DIGIMAT to LS-DYNA Interface
Dr. Jan Seyfarth, Dr.-Ing. Matthias Hörmann - CADFEM GmbH
Dr.-Ing. Roger Assaker - e-Xstream Engineering
Chandra S. Kattamuri, Bastian Grass - BSH Bosch und Siemens Hausgeräte GmbH
In the context of light weight construction the replacement of metal parts with substitutes made from plastic plays a major role. These devices commonly are manufactured through injection moulding and reinforced by different amounts of glass fibres to enhance the strength of the material. In everyday application this poses a challenge to the engineer as due to this processing the local orientation of the reinforcements is varied on a broad ...
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