Numerical Simulation for Crashworthiness of Frontal Rail Structure Using Explicit Finite Element Code

2009 ◽  
Author(s):  
Lalith Kumar R ◽  
Vinod K. Banthia
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Finite Element Code ◽  
Explicit Finite Element ◽  
Rail Structure

Numerical Simulation of Blast Loadings on a Thick-Walled Cylindrical Vessel

2007 ◽  
Author(s):  
Guide Deng ◽  
Ping Xu ◽  
Jinyang Zheng ◽  
Yongjun Chen ◽  
Yongle Hu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Dynamic Response ◽  
Rigid Wall ◽  
Cylindrical Vessel ◽  
Finite Element Code ◽  
Explicit Finite Element ◽  
Shell Deformation ◽  
Blast Loadings ◽  
Good Agreement

Determining blast loadings on an explosion containment vessel (ECV) is the foundation to design the ECV. Explosion of TNT centrally located in a thick-walled cylindrical vessel and its impact on the cylinder was simulated using the explicit finite element code LS-DYNA. Blast loadings on the cylinder computed are in good agreement with the corresponding experimental results. Then wall thickness and yield stress of the cylinder were changed in the following simulation to investigate effect of shell deformation on blast loadings. It is revealed that shell deformation during the primary pulses of blast loadings is so slight that it has little influence on the blast loadings. Though the deformation may increase greatly after the primary pulses, the dynamic response of an ECV is mainly affected by the primary pulses. Therefore, decoupled analyses are appropriate, in which the shell of an ECV is treated as a rigid wall when determining blast loadings on it.

Modeling the Dynamic Frictional Contact of Tires Using an Explicit Finite Element Code

2005 ◽  
Author(s):  
Tamer M. Wasfy ◽  
Michael J. Leamy
Keyword(s):  
Finite Element ◽  
Frictional Contact ◽  
Time Integration ◽  
Friction Model ◽  
Finite Element Code ◽  
Normal Contact ◽  
Explicit Finite Element ◽  
Beam Elements ◽  
Coulomb Friction Model ◽  
Stiffness And Damping

A time-accurate explicit time-integration finite element code is used to simulate the dynamic response of tires including tire/pavement and tire/rim frictional contact. Eight-node brick elements, which do not exhibit locking or spurious modes, are used to model the tire’s rubber. Those elements enable use of one element through the thickness for modeling the tire. The bead, tread and ply are modeled using truss or beam elements along the tire circumference and meridian directions with appropriate stiffness and damping properties. The tire wheel is modeled as a rigid cylinder. Normal contact between the tire and the wheel and between the tire and the pavement is modeled using the penalty technique. Friction is modeled using an asperity-based approximate Coulomb friction model.

ON THE PROTECTION CAPABILITY OF THE FLYING PLATE AGAINST TO LONG-ROD PENETRATORS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1285-1290
Author(s):  
STANISLAV ROLC ◽  
JAROSLAV BUCHAR ◽  
ZBYNEK AKSTEIN
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Results ◽  
Finite Element Code ◽  
Plate Material ◽  
3D Finite Element ◽  
Plate Velocity ◽  
Long Rod ◽  
Protection Capability

The interaction of the flying plate with the Long-rod penetrator has been studied both experimentally and numerically using the LS DYNA 3D finite element code. The influence of the plate velocity and plate material on this interaction has been investigated in details. Numerical results show that there was a relatively large damage of the projectiles. The extent of this damage well agree with our experimental foundings. The numerical simulation of the damaged projectiles with some targets has been also performed

Optimization of Bulk Hgcdte Growth in a Directional Solidification Furnace by Numerical Simulation

1995 ◽  
Vol 398 ◽  
Author(s):  
A.V. Bune ◽  
D.C. Gillies ◽  
S.L. Lehoczky
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Crystal Growth ◽  
Numerical Model ◽  
Directional Solidification ◽  
Growth Conditions ◽  
Finite Element Code ◽  
Interface Shape ◽  
Solidification Furnace

ABSTRACTA numerical model of heat transfer by combined conduction, radiation and convection was developed using the FIDAP finite element code for NASA's Advanced Automated Directional Solidification Furnace (AADSF). The prediction of the temperature gradient in an ampoule with HgCdTe is a necessity for the evaluation of whether or not the temperature set points for furnace heaters and the details of cartridge design ensure optimal crystal growth conditions for this material and size of crystal. A prediction of crystal/melt interface shape and the flow patterns in HgCdTe are available using a separate complementary model.

Study on the collapse of tapered tubes subjected to oblique loads

2008 ◽  
Vol 222 (11) ◽  
pp. 2025-2039 ◽  
Author(s):  
P Hosseini-Tehrani ◽  
S Pirmohammad ◽  
M Golmohammadi
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Numerical Models ◽  
Point Of View ◽  
Finite Element Code ◽  
Energy Absorber ◽  
Explicit Finite Element ◽  
Bending Deformation ◽  
Oblique Loading

In this work, several antisymmetric tapered tubes with an inner stiffener under axial and oblique loading are studied and optimum dimensions of the tapered tube are derived from a crashworthiness point of view. The importance of detecting these dimensions is optimizing the weight while the crashworthiness of tube is not damaged. By using an internal stiffener, crashworthiness is improved against oblique loads, and the sensitivity of tubes with respect to oblique loads and bending deformation is diminished. The numerical models have been developed using the explicit finite element code LS-DYNA. The crashworthiness of the optimized tapered tube is compared with that of an octagonal-cross-section tube which is known as the best energy absorber model in the literature. It is shown that an optimized tapered tube has an average of 29.3 per cent less crushing displacement in comparison with octagonal-section tube when both tubes have the same weights and the same peaks of crushing load. Finally, the orientation of loading is changed and the best orientation is proposed.

Study on the Finite Element Numerical Simulation of Automobile Crossbeam Stamping Forming

2011 ◽  
Vol 55-57 ◽  
pp. 2104-2108
Author(s):  
Xiao Chun Ma ◽  
Wei Bing Shen ◽  
Yi Qiang Zhuang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Optimal Parameter ◽  
Thickness Distribution ◽  
Metal Flow ◽  
Forming Limit Diagram ◽  
Design Parameters ◽  
Forming Limit ◽  
Explicit Finite Element ◽  
Finite Element Numerical Simulation

This paper is concerned with the quantitative effect of design parameters on the stamping process of automobile crossbeam. The considered parameters in this paper are the friction coefficient, the die fillet radius and the blank holding force, which greatly affect the metal flow during stamping. Based on the finite element numerical simulation, the stamping shaped process of the automobile crossbeam is numerical simulated with the explicit finite element method with various parameters by dint of Dynaform software. According to the simulation results, the forming limit diagram(FLD) and the wall thickness distribution of cloud on the stamping processes are technologically analyzed, the reasons and control methods of wrinkling are also pointed out, and then the optimal parameter combination of the automobile crossbeam is obtained by orthogonal experiments. It is noted that the parametric study of design parameters such as µ , BHF and RD are very important in the process design of the complicated member.

Prediction of System Natural Frequencies Using an Explicit Finite Element Code With Application to Belt-Drives

2004 ◽  
Author(s):  
Tamer Wasfy ◽  
Michael Leamy ◽  
Rick J. Meckstroth
Keyword(s):  
Finite Element ◽  
Multibody Systems ◽  
Natural Frequencies ◽  
System Response ◽  
Finite Element Code ◽  
Frequency Range ◽  
Harmonic Force ◽  
Explicit Finite Element ◽  
Belt Drives ◽  
Time Histories

A time-accurate explicit finite element code is used to predict the natural frequencies of a typical class of flexible multibody systems — automotive accessory belt-drives. The system considered consists of a belt, two pulleys, and a tensioner. Two techniques are used to find the system natural frequencies: (a) applying a sharp impulse to the system and extracting the system natural frequencies from the resulting displacement/strain time-histories via an FFT; and (b) applying a harmonic force to the system and sweeping through a frequency range, while at the same time, monitoring for large system response. In the present paper a comparison between these two techniques is presented for a typical accessory drive. Also, recommendations are offered on how to best use each technique to efficiently extract the system’s natural frequencies.

A Method of Improving Limiting Drawing Ratio：Differential Temperature Deep Drawing Based on Superplasticity

2011 ◽  
Vol 239-242 ◽  
pp. 392-397
Author(s):  
Xue Feng Xu ◽  
Ning Li ◽  
Gao Chao Wang ◽  
Hong Bo Dong
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Deep Drawing ◽  
Thickness Distribution ◽  
Coupled Analysis ◽  
Flowing Water ◽  
Finite Element Code ◽  
Uniform Thickness ◽  
Forming Process ◽  
Good Agreement

A thermal-mechanical coupled analysis of superplastic differential temperature deep drawing (SDTDD) with the MARC finite element code is performed in this paper. Initial drawing blank of an AA5083 bracket was calculated and adjusted according to the simulation result. During the SDTDD simulation, the power-law constitutive model of AA5083 was established as function of temperature and implanted in software MARC through new complied subroutine. Under the guide of the numerical simulation, the die was fabricated and the AA5083 bracket was successfully manufactured via superplastic differential temperature deep drawing. In forming practice, the temperature of female die was kept at 525°C, i.e. the optimal superplastic temperature of AA5083, and the punch was cooled by the flowing water throughout the forming process. The drawing velocity of punch was 0.1mm/s. Results revealed that the formed bracket had a sound uniform thickness distribution. Good agreement was obtained between the formed thickness profiles and the predicted ones.

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