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9th European LS-DYNA Conference

A contribution to validation of SPH new features
Thomas Beal, Nicolas Van Dorsselaer, Vincent Lapoujade (DynaS+)
Since 1998, the Smoothed Particle Hydrodynamics (SPH) method has been developed by LSTC in LS-DYNA®. This method is called a meshfree method because traditional finite elements are replaced by particles which are not physically connected but mathematically linked. It is an alternative to the classical Lagrangian Finite Elements method and is used to simulate problems where materials are submitted to hydrodynamic deformation modes, such as ...
A General Damage Initiation and Evolution Model (DIEM) in LS-DYNA
Thomas Borrvall, Thomas Johansson and Mikael Schill (DYNAmore Nordic AB), Johan Jergéus (Volvo Car Corporation), Kjell Mattiasson (Volvo Car Corporation and Chalmers University of Technology), Paul DuBois
As the automotive industry is reducing the number of physical prototypes in favour of computer simulations during their design processes, a lot of demands is put on the accuracy of the virtual finite element models used for this purpose. In this context the mathematical modelling of fracture is of major importance and has been a field of intense research over the past 50 some years. There are numerous fracture models implemented in LS-DYNA, ...
A Quadratic Pipe Element in LS-DYNA®
Tobias Olsson, Daniel Hilding (DYNAmore Nordic AB)
Analysis of long piping structures can be challenging due to the enormous number of shell/solid elements that would be required to model a piping structure accurate. In that context a new beam element has been developed that can, if used correctly, reduce the number of elements used in a pipe simulation. Since it is constructed of 3 nodes it is perfect for describing pipe bends, so called elbows. This documentimplemented inDYNA R7 [1]. is ...
Adetailedaircraft tyre finite element modellanding safety assessment for hard
Hua Guo, Christophe Bastien, Mike V. Blundell, Gary Wood (Coventry University, Dunlop Aircraft Tyres Limited)
Tyres have an important role in landing gear systems upon aircraft landing and taxing on the ground. The performances of an aircraft tyre under varied load conditions are vital requirements for aircraft safety certification. This paper describes the development of a detailed finite element (FE) model of an aircraft test tyre in order to investigate its performance and assess its safety criteria. The work follows the findings from previous ...
Advances in Simulating the Processing of Composite Materials by Electromagnetic Induction
M. Duhovic, P. Mitschang, M. Maier (Institut für Verbundwerkstoffe GmbH, Germany), I. Caldichoury, P. L'Eplattenier (LSTC)
In the previous installment of this work, a flat spiral "pancake" type coil geometry and two different plate material types with large differences in electrical and thermal conductivity (structural steel and carbon fiber reinforced polymer composite) were used to perform static plate induction heating characterization experiments for the purposes of characterizing the heating behavior of both materials in preparation for continuous induction ...
Ageing Effect on Crashworthiness of Bus Rollover
A.H. Iskandar, Q.M. Li (University of Manchester, UK)
International standards related to protection of occupants in rollover accidents are generally applied on new vehicles and regulated for design approval. However, there is no standard regulation governing rollover crash performance of aged vehicles and no proper systematic test to monitor it. It is known that vehicle structural integrity deteriorates after years of operation undergoing various service environments and conditions. The ...
AirbagApplication for Structural Racing Car Component
Alessia Prato, Marco Anghileri, Andrea Milanese (Dipartimento di Scienze e Tecnologie Aerospaziali, Italy), Chiara Marozzi (CRM Group)
In motorsports, there is a deep research in order to make cars more and more competitive, throughout an accurate study on aerodynamics, powerful and advanced engines, structural component design, materials and, of course, on racing strategy. That’s even more true when racing conditions are extremely severe, like in endurance races, such as 24 Hours of Le Mans, where changes in drivers and in racing conditions make the race more exciting. To ...
ALE Incompressible Fluid in LS-DYNA
Nicolas Aquelet, Mhamed Souli (LSTC)
The computation of fluid forces acting on a rigid or deformable structure constitutes a major problem in fluid-structure interaction. However, the majority of numerical tests consists in using two different codes to separately solve pressure of the fluid and structural displacements. In this paper, a monolithic with an ALE formulation approach is used to implicitly calculate the pressure of an incompressible fluid applied to the structure. ...
An automated belt fitting tool for 6 and 10 year-old child crash dummies
Gillian Mara, Christian Dalton (Semcon)
Modelling child occupant safety through computer aided engineering (CAE) within a vehicle is an area that is constantly developing. In 2003, Euro NCAP introduced a child occupant protection rating to inform consumers the results of vehicle safety assessments [1]. These assessments used 18 month and 3 year old dummies in frontal and side crash. Developments in technology and crash dummies have led to the introduction of new larger child ...
An Automated Process for Interior Head Impact Analysis
Thanassis Fokilidis, Antonis Perifanis (BETA CAE Systems SA), Anneli Hoegberg (VOLVO CAR Corporation)
During the last decade, the Occupant Protection legislation requirements on interior safety properties of automobiles have become considerably more demanding. The US standard laboratory test procedure FMVSS201U regulates the tests for the head protection against the event of its impact on the upper interior roof. The procedure involves the identification of the most critical target zones and headform target angles. To minimize the need for ...
Applying Digital Image Correlation Methods to SAMP-1 Characterization
Hubert Lobo, Brian Croop, Dan Roy (DatapointLabs, USA)
SAMP-1 is a complex material model designed to capture non-Mises yield and localization behavior in plastics. To perform well, it is highly dependent on accurate post-yield material data. A number of assumptions and approximations are currently used to translate measured stress-strain data into the material parameters related to these inputs. In this paper, we look at the use of direct localized strain measurements using digital image ...
Assessment Of Mach Stem Pressures: Comparison Of Experiments With Engineering And Eulerian Models
Len Schwer (Schwer Engineering & Consulting Services)
Laboratory scale tests conducted by Kisters and Kuder (2012) provide reflected pressure histories for a 1kg TNT charge detonated at 0.32m above a rigid surface. The pressure histories are measured 1m from the charge using a vertical array of pressure transducers to infer the height of the Mach Stem at this range. Two such vertical arrays, each with 9 pressure transducers at varying heights above the surface, were used, and the test was ...
BEM Methods For acoustic and vibroacoustic problems in LSDYNA
Souli Mhamed, Yuang Yun, Zhe Cui, Zeguar Tayeb (LSTC)
The present work concerns the new capability of LS-DYNA in solving acoustic and vibroacoustic problems in time domain and frequency domain, using the following LSDYNA Cards: *MAT_ACOUSTIC *FREQUENCY_DOMAIN_ACOUSTIC_BEM *FREQUENCY_DOMAIN_ACOUSTIC_FEM *FREQUENCY_DOMAIN_SSD In vibroacoustic problems, which are assumed to be weak acoustic-structure interactions, the transient structural response is computed first. By applying the FFT, it is ...
Buried Charge Engineering Model: Verification And Validation
Len Schwer (Schwer Engineering & Consulting Services), Todd Slavik (LSTC)
Livermore Software Technology Corporation (LSTC) recently added an empirically-based model for buried mine blast loading via the keyword *INITIAL_IMPULSE_MINE. This is an engineering model based upon experimental results, much like the air blast engineering model provided by *LOAD_BLAST_ENHNACED. The model is based on the work of Westine, et al. (1985) as presented, and extended, by Tremblay (1998). The implementation is applicable to flat ...
Closing the Gap between Process- and Crash Simulation for Composite Materials
Ch. Liebold, A. Haufe (DYNAmore GmbH, Germany), H. Finckh (Deutsches Institut für Textil- und Faserforschung Denkendor, Germany), T. Günther(Volume Graphics GmbH, Germany)
The usage of fiber reinforced plastics (FRP) becomes more and more important in the automotive industry and therefore, the requirements for accurate crash analysis results for such materials increase. As already known from sheet metal forming, process simulations are performed to predict fiber orientations for all kinds of short, long or endless fiber reinforced parts, even though most of the available software tools only use geometrical ...
Development of special new versions of the FAT/PDB Dummy models for quick analysis response. The Rapid Analysis Models (R.A.M.)
Reuben D’Souza, Yupeng Huang, Sebastian Stahlschmidt (DYNAmore GmbH, Germany)
The finite element model of the FAT and PDB Dummy models have been developed in co-operation with the German Automotive lndustry for the last few years, One of the major goals during the development of the models was to achieve a high degree of accuracy of the model as well as to have a robust model without numerical instabilities. During the course of the model development, the geometry of various components has evolved considerably and ...
Drilling process modelling using SPH
Virginija Gyliene, Vytautas Ostasevicius, Martynas Ubartas (Kaunas University of Technology, Lithuania)
Numerical methods became a powerful tool to understand such complicated process as cutting processes. Based on finite element techniques, firstly a big challenge – geometric modeling of bodies coming in contact interaction and mesh size/zone choice and creation. Secondly, today’s we now that finite element modeling is sure tool in the research of cutting processes after many series of experiments. So, here is the purpose to get reliable ...
Drilling rotation constraint for shell elements in implicit and explicit analyses
Tobias Erhart (DYNAmore GmbH, Germany), Thomas Borrvall (DYNAmore Nordic AB, Sweden)
A subordinate but interesting detail in theory and application of shell elements is investigated in this study, namely the drilling rotation constraint approach. Standard shell elements exhibit 3 translational and 3 rotational degrees-of-freedom at each node. While two nodal rotations are directly associated with bending and twisting modes, the third rotation about the shell normal (also known as the drilling rotation) does not provide any ...
Evaluation of a dummy design by using a human body model
Christian Gehre, Norbert Praxl (PDB), Sebastian Stahlschmidt, Dirk Freßmann (DYNAmore GmbH)
Human body models for occupant protection became popular in the last years. They started to turn from high sophisticated research tools to reasonably applicable tools to support some specific areas of occupant safety. This study is focused on the evaluation of the BioRID-II shoulder design by using the THUMS human body model. After the introduction of the BioRID-II into several test protocols to assess whiplash associated disorder, some ...
Experimental Investigation and FE Modeling of the High Temperature Dynamic Properties of Metals in the Kolsky method
Pavel A. Mossakovsky, Alexander V. Inyuhin, Fedor K. Antonov (Reaserch Institute of Mechanics of Lomonosov Moscow State University, Russia), Liliya A. Kostyreva (FSUE "GTERPC 'Salut", Russia)
In a wide range of practical problem on the dynamic strength associated with the impact and penetration an adequate definition of the material properties as a strain rate and temperature function has a great importance. One of the most effective and reliable methods for determining materials properties at high strain rates is the Kolsky method using the split Hopkinson bar [1]. This method is based on the one-dimensional theory of elastic ...
FE Fracture Prediction on Edges of Punched Holes
Dr Janka Cafolla, David P. Norman (Tata Steel UK Limited)
Many industry sources identified fracture from holes and edges as a key knowledge gap for fracture prediction of AHSS and UHSS grades. Ford Aachen with MATFEM cooperation [1] has shown an importance of including fracture failure models into their finite element (FE) simulations especially when designing with UHSS such as Boron Steel. Hole expansion coefficient (HEC) is one of the ways to characterise the edge cracking of metals. Many ...
Finite Element Modeling of Aluminium Honeycomb with Variable Crush Strength and Its Application in AE-MDB Model
M. Asadi (Anglia Ruskin University), B. Walker, H. Mebrahtu (ARUP Campus (UK)), M. Ashmead (Cellbond (A Division of Encocam Ltd.))
Aluminium honeycomb blocks are often to gain differentiated crush strength pattern to represent variable behavior while subjected to static/dynamic deformation. Current article demonstrates the methodology to validate modeling techniques and implementing in a finite element model for the Advanced European Mobile Deformable Barrier (AE-MDB). AE-MDB v3.9 side impact barrier has been investigated in present paper. The FE model is then examined ...
Finite element modelling and validation of the honeycombs for automobile crash MDB and ODB
Hui Yang, Qianbo Liu, Liangfu Yu (Shanghai Motor Vehicle Inspection Centre), Lin Li (Automotive College of Tongji University)
Honeycomb materials are widely used in automotive crash tests. Typically, it is the main components of the ODB (Offset Deformable Barrier) and MDB (Mobile Deformable Barrier) stipulated in ECE Regulation No.94 and No.95 on automotive crash test. These two kinds of honeycombs or barriers are also adopted by Chinese regulations. The accuracy and efficiency are most important for the CAE analysis of automotive crash simulation. In the earlier ...
Fluid-Structure Interaction involving Close-in Detonation Effects on Column using LBE MM-ALE Method
Swee Hong Tan, Shih Kwang Tay, Jiing Koon Poon, David Chng (ministry Of Home Affairs, Singapore)
This paper shares the experiences gathered from studies conducted on the use of *Load_Blast_Enhanced (LBE) keyword to couple empirical blast loads to air domain in Multi-Material Arbitrary Lagrangian-Euler (MM-ALE) environment and on Fluid-Structure Interaction (FSI) computations relating to various aspects of coupling technique in LS-DYNA® via *Constrained_Lagrange_in_Solid keyword for structures composing of mainly solid elements. This ...
Following Nature’s Lead for Ultimate Design Efficiency The ACP Process as Applied to FSV
Akbar Farahani (ETA Inc.), Jody Shaw (U.S. Steel)
The shapes and configurations of nature are wildly complicated, non-intuitive and completely amazing. The shapes and forms found in nature in the structure of a tree, a human skeleton, insects and animals are truly the most efficient designs imaginable. By mimicking the flawless balance between structure and strength of nature’s most efficient shapes, engineers can learn how to incorporate similar balance to product structural design for ...
GasDynamic Simulation Capability for Side Impact Pressure Sensing Calibration
Bill Feng, Amarjit Grewal (Body CAE, Jaguar Land Rover Ltd), Steve Hickman, Dave Moore, Alexandro Badea-Romero (Vehicle Safety, Jaguar Land Rover Ltd), Christian Dalton (Semcon Engineering)
A method has been developed that uses crash simulation models to provide side impact door pressure sensor data to the sensor calibration engineers much earlier than was hitherto possible, thereby affording the opportunity to reduce the time period required for physical sensor calibration in the vehicle development programme.
Head of Leveraging LS-DYNA Explicit, Implicit, Hybrid technologies with SGI hardware, Cyclone Cloud Bursting and d3VIEW
Olivier Schreiber, Tony DeVarco, Scott Shaw (SGI), Suri Bala (LSTC)
LSTC Explicit, Implicit solver technologies are closely integrated following LSTC's single executable strategy. Seamless switching from large time steps transient dynamics to linear statics and normal modes analysis can thus consistently exploit latest algorithm improvements in Shared Memory Parallelism (SMP), Distributed Memory Parallelism (DMP) and their combination (Hybrid Mode) and leverage SGI computer architectures using SGI's software ...
Influence of Contact Parameters on Short-Event Crash Simulation Results
Nick Kalargeros, Jack Perry, Antonio Peralta, Lee Pearce (Jaguar Land Rover Limited)
The aim of a vehicle crash simulation is to characterise and quantify the performance of specific regions in terms of energy dissipation, distribution and intensity. Such detailed understanding of the crash event will enable the analysis and prediction of occupant and / or pedestrian injuries. To achieve this, an interacting chain of individual components and systems need to be studied in terms of its energy management and absorption ...
Influence of Discretisation on Stiffness and Failure Prediction in Crashworthiness Simulation of Automotive High Pressure Die Cast Components
Felix Brenner, Helmut Gese, Gernot Oberhofer (MATFEM Partnerschaft Dr. Gese & Oberhofer), Michael Buckley (Jaguar Land Rover Limited)
Castings are widely used as part of the car chassis in automobile manufacture because of their light weight and the flexibility of the design process. Due to the comparable low ductility of castings, it is essential for crash simulations to gain dependable analyses. However, modelling casting parts correctly for finite element analyses is an issue for several reasons. In order to represent the elastoplastic stiffness correctly and thus to ...
InteractionPossibilities of Bonded and Loose Particles in LS-DYNA®
Nils Karajan (DYNAmore GmbH, Germany), Zhidong Han, Hailong Ten, Jason Wang (LSTC)
The goal of this presentation is to outline the current development status of LS-DYNA® with respect to simulations using the discrete-element method (DEM), which is based on Cundall & Strack [1]. Starting with assemblies of loose discrete spherical particles, different types of granular media can be discretized to predict their behavior, for instance, during mixing processes, storage and discharge in silos or transportation on belts. ...
JFOLD - Introducing A New Simulation-Based Airbag Folding System for LS-DYNA®
Shinya Hayashi (JSOL Corporation)
Computer simulation is playing an increasingly important role in the design, development and application of airbag safety systems. As folding patterns and airbag structures become more and more complex, users are turning to simulation based folding solutions to generate accurately folded models in a short space of time. To meet this demand, a new software tool called JFOLD has been developed by JSOL Corporation to enable successful airbag ...
LS-DYNA® R7: Conjugate heat transfer problems and coupling between the Incompressible CFD (ICFD) solver and the thermal solver, applications, results and examples.
Iñaki Çaldichoury, Facundo Del Pin (LSTC)
LS-DYNA version R7 includes CFD solvers for both compressible and incompressible flows. The incompressible CFD solver (ICFD) may run as a stand alone CFD solver for pure thermal fluid problems or it can be strongly coupled using a monolithical approach with the LS-DYNA solid thermal solver in order to solve the complete conjugate heat transfer problem. This paper will focus on the thermal part of the ICFDthermal and conjugate heat transfer ...
LS-DYNA® R7: Coupled Multiphysics analysis involving Electromagnetism (EM), Incompressible CFD (ICFD) and solid mechanics thermal solver for conjugate heat transfer problem solving
Iñaki Çaldichoury, Pierre L'Eplattenier, Facundo del Pin (LSTC), Miro Duhovic (Institut für Verbundwerkstoffe GmbH)
LS DYNA R7’s new modules and capabilities include: two fluid mechanics (CFD) solvers for incompressible (ICFD) and compressible flows (CESE) and an Electromagnetism solver (EM). The objective of these solvers is not only to solve for their particular domain of physics but to make full use of LS-DYNA capabilities and material library in order to solve coupled multiphysics. This paper will present how the EM solver can solve inductive heating ...
LS-DYNA® R7: Recent developments, application areas and validation results of the compressible fluid solver (CESE) specialized in high speed flows.
Zeng-Chan Zhang, Iñaki Çaldichoury (LSTC)
LS-DYNA version R7 includes CFD solvers for both compressible and incompressible flows. The compressible flow solver is based on the CESE method, a novel numerical method for solving conservation laws. It has many nontraditional features such as space-time conservation, second order accuracy for flow variables and a powerful shock wave capturing strategy. This paper will focus on some advanced features of the solver namely its FSI ...
LS-DYNA® R7: Strong Fluid Structure Interaction (FSI) capabilities and associated meshing tools for the incompressible CFD solver (ICFD), applications and examples.
Facundo Del Pin, Iñaki Çaldichoury (LSTC)
LS-DYNA version R7 includes CFD solvers for both compressible and incompressible flows. The solvers may run as standalone CFD solvers or they could be coupled to the LS-DYNA solid mechanics and thermal solvers for fluid structure interaction (FSI) and conjugate heat transfer problems. This paper will focus on the Incompressible CFD solver in LS-DYNA (ICFD) and its Fluid-solid interaction capabilities (FSI). Fluid structure interaction ...
LS-DYNA®R7:Update On The Electromagnetism Module (EM)
Pierre L'Eplattenier, Iñaki Çaldichoury, Julie Anton (LSTC)
An electromagnetism module is being developed in LS-DYNA version R7 double precision for coupled mechanical/thermal/electromagnetic simulations. The physics, numerical methods and capabilities of this module will be introduced. Some examples of industrial applications will be presented. These include magnetic metal forming, bending and welding in different configurations, high pressure generation for equation of state studies and material ...
LS-OPT Parameters Identification on Concrete Sample Tests for an Impact Simulation on Concrete Slab
Nicolas Van Dorsselaer, Vincent Lapoujade (DynaS+), Georges Nahas, Bertrand Ciree, François Tarallo, Jean-Mathieu Rambach (Institut de Radioprotection et de Sûreté Nucléaire)
The dynamic behavior of Concrete is one of the most common and difficult problem of simulation in Nuclear, Defense and Civil fields. In most cases, the data available for modeling problems is much reduced; engineers are obliged to predict the behavior with non sufficient information. Due to this lack of experimental sample based input parameters, the result of simulation becomes “engineer dependent”, leading to much different results than ...
Modeling of Punctual Joints for Carbon Fiber Reinforced Plastics (CFRP) with *MAT_054
Christian Liebold (DYNAmore GmbH, Germany), David Moncayo (Daimler AG, Germany)
The increasing amount of carbon fiber reinforced plastic (CFRP) components used in the automotive industry opens new questions concerning the numerical modeling of different joining techniques for such materials. Design engineers already know that the beneficial properties of carbon fibers can be best used when considering the necessary joining techniques from the very first step in the preliminary design of a CFRP part. The anisotropical ...
Modelling internal gas flows in a single stage gas gun using Eulerian/Lagrangian coupling in LS-DYNA
Marina Seidl, Kevin Hughes, Tom De Vuyst (Cranfield University)
Most research on gas guns for impact testing investigates the velocity reached by the projectile or sabot when it hits the target. In this research attention is paid to the effect of initial loading conditions on the velocity reached by the projectile upon exit from the barrel. The work is focussed on the single stage nitrogen gas gun at the Department of Applied Mechanics in the School of Engineering at Cranfield University of this ...
Modelling Spotweld Fracture Using CrachFEM
D. P. Norman (TATA Steel UK Limited)
In recent years, a number of research institutes have concentrated on trying to develop fracture models that are generally applicable to a wide range of engineering problems. Examples of some of these fracture models are from Gurson and various extensions to Gurson[1], Dell and Gese (CrachFEM)[2], Xue-Wierzbicki[3], Wilkins (EWK model)[4], and du Bois (*MAT_GISSMO)[5]. The key features of these models are a dependency of the fracture strain ...
Models for strain path independent necking prediction in LS-DYNA
Kjell Mattiasson (Chalmers University of Technology, Volvo Cars Safety Centre) , Johan Jergeus (Volvo Cars Safety Centre), Paul Dubois (Hermes Engineering NV)
Failure in sheet metal can be caused by one of, or a combination of, the following mechanisms: ductille fracture, shear fracture and plastic instability (necking). Ductile fracture is causrd by the initiation, growth and coalescence of voids in the material during plastic straining, commonly referred to as damage growth. Micro defects can also lead to through-thickness shear fracture in the sheet metal. There are several difIerent ...
Multi-disciplinary Topology Optimization for Vehicle Bonnet Design
David Salway (GRM Consulting Ltd), Tayeb Zeguer (Jaguar Land Rover Ltd)
Bonnet Pedestrian Head lmpact and Structural Stiffness and Strength targets have conflicting design requirements which currently result in design compromises, and the current CAE methods use different models and solvers. This paper highlights a new CAE capability to provide Multi-Disciplinary Optimization of bonnet geomety to achieve the conflicting Pedestrian Head Impact and structural stiffness/strength targets at lowest weight and cost. ...
New material modeling approaches for thermoplastics, composites and organic sheet
Matthias Vogler (Consulting engineer, Germany)
In this paper, new anisotropic elastic-viscoplastic constitutive models for simulating thermoplastic materials, endless fiber reinforced composites and organic sheets are presented. The anisotropic material models address the same main features as the isotropic SAMP model (MAT_187 in LS-DYNA). These are in particular pressure dependent yielding allowing for different yielding in tension, compression, shear and biaxial loadings, tabulated ...
Node to node contacts for SPH applied to multiple fluids with large density ratio
Jingxiao Xu, Jason Wang (LSTC)
The interesting and complex behavior of fluids emerges mainly from interaction processes. SPH has shown to be a simple, yet flexible method to cope with many fluid simulation problems in a robust way. However in SPH, particles have a spatial distance (smoothing length) over which their properties are smoothed by a kernel function. Smoothed quantities of a particles show falsified values when densities and masses of neighboring particles vary ...
Non-Linear Time History Analysis of Tall Steel Moment Frame Buildings in LS-DYNA
Carlos Molina Hutt (UCL)
® Non-linear time history analyses were carried out in LS-DYNA (LSTC) in order to assess the seismic performance of existing tall steel moment resisting framed buildings. Ground motion earthquake records representative of the Maximum Considered Earthquake (MCE) hazard level defined in current building codes were used in the analysis. This paper focuses on the different component models utilized to capture the complex non-linear elements of ...
Numerical Determination of Permeability Tensor Components for 3D-braided Composites Using RVC Approach
Fedor K. Antonov (Research Institute of Mechanics of Lomonosov Moscow State University)
Today, one of the most promising trends in the design and manufacturing of composite structures is the use of 3D-reinforced thermoplastic composites. The present paper is concerned with the problem of resin transfer molding (RTM) process modeling, which is an important stage of 3D thermoplastic composites design. It is known that during the impregnation of woven preform local starved spots may occur, the textile pattern may distort and as a ...
Numerical Evaluation of an Add-On Vehicle Protection System
Geneviève Toussaint, Amal Bouamoul, Robert Durocher, Benoît St-Jean (Defence Research and Development Canada), Jacob Bélanger (Numerica Technologies Inc)
Defence Research and Development Canada (DRDC) has been involved in programs to reduce the vulnerability of vehicles to mines and improvised explosive devices for many years. In this work, DRDC was mandated to design and optimize an add-on vehicle protection system. Testing an entire vehicle against improvised explosive devices or blast landmines is both time-consuming and “expensive; therefore, to reduce costs, numerical simulations using ...
Numerical Simulation of Elastic-Plastic Deformation of Aircraft Fuel Tank Access Cover Impacted by Tyre Fragment
Alexander A. Ryabov, Vladimir I. Romanov, Sergey S. Kukanov, Anatoliy K. Botvinkin (Sarov Engineering Center)
All new-designed passenger aircrafts have to meet strict national and international safety requirements in accidents. One of the possible accidents is pneumatic tire damage, which can become the reason of the tire tread fragmenting. Some fragments of the tire tread with different mass and velocity can impact and break different plane elements. According to the safety requirements the designing company has to prove that the new plane ...
NVH and Random Vibration Fatigue Analysis of a Landing Gears's Leg for an Un-Manned Aerial Vehicle Using LS-DYNA®
Al-Bahkali Essam, Elkenani Hisham (King Saud University), Souli Mhamed (Universite de Lille)
The present work concerns the new capability of LS-DYNA in solving Noise, Vibration and Harshness (NVH) and fatigue based on Power Spectrum Density (PSD) analysis. These new capability includes random vibration and high-cycle fatigue analysis in a random vibration environment. In this analysis, the cumultative damage ratio of a landing gear's leg for an Un-Manned Aerial Vehicle (UAV) is computed using material S-N (Stress-Number of cycles) ...
On The Feng Failure Criterion For Composites
William W. Feng, John O. Hallquist, David J. Benson (LSTC)
In this paper, the criterion is evaluated with experimental data for a boron/epoxy, symmetrically balanced, angle-ply laminate. The results prove that the failure states obtained by the criterion agree with the experimental data. Furthermore, the criterion also predicts whether the failure of a composite is due to matrix or fiber. The advantages for Feng failure criterion over other criteria are summarized, and the criterion is ...