scholarly journals Head Injury Reduction in Automobile Pedestrian Impact

1994 ◽  
Vol 1 (6) ◽  
pp. 559-568
Author(s):  
David R. Lemmon ◽  
Ming-yi Wu ◽  
Ronald L. Huston
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Nonlinear Dynamic ◽  
Finite Element Program ◽  
Injury Reduction ◽  
Head Injury Criterion ◽  
Dynamic Finite Element ◽  
Element Program ◽  
Automobile Hood ◽  
Pedestrian Impact

This article presents and discusses automobile hood/fender rail design to reduce head injury of pedestrians struck by the front of the vehicle. Fender seam designs are presented that reduce the head injury criterion values by over 50%. The procedures and analysis are conducted using a nonlinear dynamic finite element program for an Oldsmobile Ciera hood and a Ford Taurus hood/fender.

Automobile Hood/Fender Design Optimization for Improved Pedestrian Head Impact Protection

1994 ◽  
Author(s):  
David R. Lemmon ◽  
Ronald L. Huston
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Structure Design ◽  
Head Impact ◽  
Design Parameters ◽  
Head Injury Criterion ◽  
Dynamic Finite Element ◽  
Automobile Hood ◽  
Impact Protection ◽  
Related Design

Abstract This paper presents procedures for automobile structure design to reduce head injury of pedestrians struck by the vehicle. The fender and hood seam of a 1988 Ford Taurus are modified to absorb the energy of a head impact. Two shape related design parameters are optimized for minimum Head Injury Criterion using finite element simulations. A design is presented which reduces Head Injury Criterion by over 50 percent. All analyses are conducted using the explicit, nonlinear, dynamic finite element code DYNA3D on a Cray YMP/832 supercomputer.

Implementation of the Nonlocal Microplane Concrete Model Within an Explicit Dynamic Finite Element Program

1992 ◽  
Vol 45 (3S) ◽  
pp. S132-S139 ◽  
Author(s):  
William F. Cofer
Keyword(s):  
Finite Element ◽  
Strain Tensor ◽  
Material Model ◽  
Material Behavior ◽  
Concrete Material ◽  
Finite Element Program ◽  
Dynamic Finite Element ◽  
Weighted Integral ◽  
Element Program ◽  
Explicit Dynamic

The microplane concrete material model is based upon assumptions regarding the behavior of the material components. At any point, the response to the strain tensor on arbitrarily oriented surfaces is considered. Simple, softening stress-strain relationships are assumed in directions perpendicular and parallel to the surfaces. The macroscopic material behavior is then composed of the sum of the effects. The implementation of this model into the explicit, nonlinear, dynamic finite element program, DYNA3D, is described. To avoid the spurious mesh sensitivity that accompanies material failure, a weighted integral strain averaging approach is used to ensure that softening is nonlocal. This method is shown to be effective for limiting the failure zone in a concrete rod subjected to an impulse loading.

Dynamic Finite Element Analysis for Contact Stress of Dynamic Consolidation

2013 ◽  
Vol 353-356 ◽  
pp. 502-506
Author(s):  
Fu Yuan Zhang ◽  
Deng Yuan Zhu ◽  
Shou Ren Ge ◽  
Xiao Bao Sun
Keyword(s):  
Finite Element ◽  
Contact Stress ◽  
Stress Condition ◽  
Element Analysis ◽  
Finite Element Program ◽  
Dynamic Finite Element ◽  
Dynamic Finite Element Analysis ◽  
Dynamic Consolidation ◽  
Element Program ◽  
Contact Stress Distribution

Based on Abaqus/explicit dynamics finite element program, an ax symmetrical numerical model, the infinite fringe condition and friction contact condition were built, and then the surface contact stress condition of the dynamic consolidation was studied. The time-load properties of dynamic consolidation, the spread law of contact pressure for rammer bottom and the friction influence to contact stress between the hammer and foundation were gained. The results indicate that the dynamic consolidation load can be simplified to triangular load with the weight of the hammer itself; the contact stress distribution between the hammer and the foundation is not uniform; and frictionless contact hypothesis can led errors to the simulated result.

Finite Element Study of Pressure Wave Attenuation by Reactor Fuel Subassemblies

1975 ◽  
Vol 97 (3) ◽  
pp. 172-177 ◽  
Author(s):  
T. Belytschko ◽  
J. M. Kennedy
Keyword(s):  
Finite Element ◽  
Wave Attenuation ◽  
Reactor Core ◽  
Finite Element Program ◽  
Beam Elements ◽  
Dynamic Finite Element ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Complex Boundary ◽  
Surrounding Fluid

The attenuation of pressure waves by the subassembly walls in a reactor core was studied by a two dimensional, finite element program. For these purposes, a hydro-dynamic finite element was incorporated in an existing dynamic structural program. The resulting program has the advantage that complex boundary conditions and the interaction of structural and fluid elements are handled in a straightforward manner. The program was used to model a section of the hexcan and the surrounding fluid; the hexcan was modelled by beam elements. It is shown that the hexcan walls attenuate pressure peaks by about 33 percent in the adjacent subassembly. Thus the subassembly walls may play an important role in confining the effects of local accidents.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Finite Element Analysis on the Deformation of Energy-Saving Wire-Mesh Frame Wallboard

2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Energy Saving ◽  
Theoretical Basis ◽  
Steel Wire ◽  
Wire Mesh ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Influence Degree

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.

scholarly journals Numerical Analyses of Earthquake Induced Liquefaction and Deformation Behaviour of an Upstream Tailings Dam

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Auchar Zardari ◽  
Hans Mattsson ◽  
Sven Knutsson ◽  
Muhammad Shehzad Khalid ◽  
Maria V. S. Ask ◽  
...  
Keyword(s):  
Finite Element ◽  
Seismic Event ◽  
Deformation Behaviour ◽  
Ground Surface ◽  
Tailings Dam ◽  
Limited Extent ◽  
Northern Sweden ◽  
Finite Element Program ◽  
Dynamic Analyses ◽  
Element Program

Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes.

Sign in / Sign up

Export Citation Format

Share Document