Reducing Occupant Injury in Frontal Crashes for a Low-Floor City Bus

2005 ◽  
Author(s):  
Elham Sahraei Esfahani ◽  
Kurosh Darvish ◽  
Mohamad Parnianpour ◽  
Akbar Bateni
Keyword(s):  
Plastic Material ◽  
Material Model ◽  
Element Model ◽  
Driver Model ◽  
City Bus ◽  
Hybrid Iii ◽  
Occupant Injury ◽  
Occupant Injuries ◽  
Frontal Crashes ◽  
Elastic Plastic Material

In this research, the effect of beam buckling in a predefined direction is used to reduce occupant injuries in frontal crashes of an ultra-low-floor (ULF) city bus. In ULF buses, the floor structure consists of several longitudinal long beams, which in case of a frontal crash may buckle due to the axial impact. The direction of rotational acceleration of the driver seat due to buckling is highly affected by the position of the driver seat. A finite element model of an ULF bus was developed using LS-Dyna. The driver model, a Hybrid III 50th male dummy with deformable jacket and abdomen, was restrained to the seat with a 3-point belt. An Elastic-Plastic material model was used for the bus structure to investigate the buckling behavior of the beam elements. Using diagonal beams to guide the buckling in a desired direction, rewarding results were achieved in reducing the occupant injuries. For example, with an extra diagonal beam under the seat, the driver’s HIC15 was reduced from 739 to 415.7 and HIC36 from 791 to 700.6.

A Continued Evaluation of the Role of Material Hardening Behavior for the NeT TG1 and TG4 Specimens

2014 ◽  
Author(s):  
David J. Dewees ◽  
Phillip E. Prueter ◽  
Seetha Ramudu Kummari
Keyword(s):  
Structural Integrity ◽  
Plastic Material ◽  
Critical Factor ◽  
Material Model ◽  
Standard Test ◽  
Material Behavior ◽  
Weld Residual Stress ◽  
Hardening Models ◽  
Elastic Plastic Material

Modeling of cyclic elastic-plastic material behavior (hardening) has been widely identified as a critical factor in the finite element (FE) simulation of weld residual stresses. The European Network on Neutron Techniques Standardization for Structural Integrity (NeT) Project has provided in recent years both standard test cases for simulation and measurement, as well as comprehensive material characterization. This has allowed the role of hardening in simulation predictions to be isolated and critically evaluated as never before possible. The material testing information is reviewed, and isotropic, nonlinear kinematic and combined hardening models are formulated and tested. Particular emphasis is placed on material model selection for general fitness-for-service assessments, as it relates to the guidance for weld residual stress (WRS) in flaw assessments of in-service equipment in Annex E of the FFS standard, API 579-1/ASME FFS-1.

Experiment and Elastic-Plastic Modelling of the IPN160 Beam

2015 ◽  
Vol 769 ◽  
pp. 331-335
Author(s):  
Jakub Vasek ◽  
Oldrich Sucharda
Keyword(s):  
Computational Models ◽  
Plastic Material ◽  
Numerical Models ◽  
Steel Structure ◽  
Material Model ◽  
Nonlinear Material ◽  
Software Application ◽  
Elastic Plastic ◽  
Elastic Plastic Material ◽  
Isoparametric Finite Elements

The paper compares the numerical models of and experiments with a beam. The purpose is to evaluate the nonlinear material model of a steel structure. The steel is modelled as an ideal elastic-plastic material. The FEM and eight-node isoparametric finite elements are considered in the analysis. The 3D calculations use different material constants and several approaches are being tested in order to create the computational models. The calculations are performed in the software application developed by our university.

Study on Impinging Stream Flow Channel in Abrasive Flow Polishing Complex Cavity of Precision Mold

2013 ◽  
Vol 797 ◽  
pp. 469-474
Author(s):  
Di Feng Zhou ◽  
Dong Yu Liu
Keyword(s):  
Stream Flow ◽  
Plastic Material ◽  
Material Model ◽  
Impact Deformation ◽  
Element Simulation ◽  
Complex Cavity ◽  
Elastic Plastic Material ◽  
Set Up ◽  
The Impact ◽  
Abrasive Flow Polishing

In order to solve the problem about polishing complex cavity of precision mold, to improve the efficiency of processing and reduce the surface roughness, putting forward multiple entries impinging stream processing device.With making use of the collision of two strands of abrasive flow, Realizing the mutual disturbance of abrasive flow in the runner, and increasing the collision between abrasive to improve the disordering of abrasive movement, for promoting abrasive polishing to mold cavity. Johnson-Cook elastic-plastic material model is set up at the same time, using abaqus finite element simulation to simulate the impact deformation wear and cutting wear with the increasment of impact times.

Calibration of Elastic-Plastic Material Model for Tire Shreds

2004 ◽  
Author(s):  
Boris Jeremić ◽  
James Putnam ◽  
Kallol Sett ◽  
Dana Humphrey ◽  
Stacey Patenaude
Keyword(s):  
Plastic Material ◽  
Material Model ◽  
Elastic Plastic ◽  
Tire Shreds ◽  
Elastic Plastic Material

NONLINEAR FINITE ELEMENT ANALYSIS OF FRP STRENGTHENED RC BEAMS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Prabin Pathak ◽  
Y. X. Zhang
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Experimental Studies ◽  
Material Model ◽  
Element Model ◽  
Steel Reinforcement ◽  
Elastic Model ◽  
Fe Model ◽  
Rc Beams ◽  
Element Analysis

A simple, accurate and efficient finite element model is developed in ANSYS for numerical modelling of the nonlinear structural behavior of FRP strengthened RC beams under static loading in this paper. Geometric nonlinearity and material non-linear properties of concrete and steel rebar are accounted for this model. Concrete and steel reinforcement are modelled using Solid 65 element and Link 180 element, and FRP and adhesive are modelled using Shell 181element and Solid 45 element. Concrete is modelled using Nitereka and Neal’s model for compression, and isotropic and linear elastic model before cracking with strength gradually reducing to zero after cracking for tension. For steel reinforcement, the elastic perfectly plastic material model is used. FRPs are assumed to be linearly elastic until rupture and epoxy is assumed to be linearly elastic. The new FE model is validated by comparing the computed results with those obtained from experimental studies.

An Adaptive Pressbrake Control for Strain-Hardening Materials

1986 ◽  
Vol 108 (2) ◽  
pp. 127-132 ◽  
Author(s):  
K. A. Stelson
Keyword(s):  
Strain Hardening ◽  
Material Property ◽  
Plastic Material ◽  
Material Model ◽  
Punch Force ◽  
Elastic Plastic ◽  
The Press ◽  
Elastic Plastic Material ◽  
Thickness Variations ◽  
Force Displacement

An improved adaptive pressbrake control algorithm is described. The problem is to control the punch reversal position of the press so that the final unloaded angle of the bend remains unchanged in the presence of material property and thickness variations of the sheets or plates being bent. Pressbrake control algorithms that use punch force-displacement data to identify thickness and material property variations have shown promise. However, since previous controllers have been based on an elastic-plastic material model, the parts have been overbent. In this paper, a controller based on an elastic, power-law strain-hardening model is proposed. Experiments have shown that the model eliminates the tendency to overbend the parts that is present in the elastic-plastic algorithm.

Finite Element Modeling of Blast Lung Injury in Sheep

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Melissa M. Gibbons ◽  
Xinglai Dang ◽  
Mark Adkins ◽  
Brian Powell ◽  
Philemon Chan
Keyword(s):  
Finite Element ◽  
Lung Injury ◽  
Plastic Material ◽  
Field Testing ◽  
Material Model ◽  
Threshold Value ◽  
Element Model ◽  
Blast Overpressure ◽  
Strain And Strain Rate ◽  
Blast Lung Injury

A detailed 3D finite element model (FEM) of the sheep thorax was developed to predict heterogeneous and volumetric lung injury due to blast. A shared node mesh of the sheep thorax was constructed from a computed tomography (CT) scan of a sheep cadaver, and while most material properties were taken from literature, an elastic–plastic material model was used for the ribs based on three-point bending experiments performed on sheep rib specimens. Anesthetized sheep were blasted in an enclosure, and blast overpressure data were collected using the blast test device (BTD), while surface lung injury was quantified during necropsy. Matching blasts were simulated using the sheep thorax FEM. Surface lung injury in the FEM was matched to pathology reports by setting a threshold value of the scalar output termed the strain product (maximum value of the dot product of strain and strain-rate vectors over all simulation time) in the surface elements. Volumetric lung injury was quantified by applying the threshold value to all elements in the model lungs, and a correlation was found between predicted volumetric injury and measured postblast lung weights. All predictions are made for the left and right lungs separately. This work represents a significant step toward the prediction of localized and heterogeneous blast lung injury, as well as volumetric injury, which was not recorded during field testing for sheep.

Study on Drilling Force of Pore for Hard-to-Cut Material

2010 ◽  
Vol 455 ◽  
pp. 521-524
Author(s):  
Yong Tang ◽  
Bang Yan Ye ◽  
X.F. Hu ◽  
Qiang Wu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Metal Cutting ◽  
Plastic Material ◽  
Material Model ◽  
Element Model ◽  
Drilling Process ◽  
Drilling Force ◽  
Rigid Plastic ◽  
Key Techniques

This paper studies drilling force of pore for hard-cutting material based on theoretical and experimental investigation during pore drilling process. A coupled thermo-mechanical finite element model of metal pore drilling process was established. Some key techniques such as material model, chip separation and damage criteria and dynamic mesh self-adapting technology in the finite element simulation of metal cutting process were discussed in details. The paper simulated dynamically the chip formation of the twist drilling process in which rigid plastic material model was selected for workpieces and thermal rigid models for tools. The results indicate that the proposed finite element model is not only correct but also feasible in the prediction of the variations of drilling force and torque with amount of feed.

Fitness for Service Assessment on Local Metal Loss Near a Discontinuity Using Elastic-Plastic Stress Analysis

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Zhanghai (John) Wang ◽  
Samuel Rodriguez
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Plastic Material ◽  
Material Model ◽  
Metal Loss ◽  
Technical Approach ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Structural Discontinuity ◽  
Elastic Plastic Material

In fitness for service (FFS) assessments, one issue that people often encounter is a corroded area near a structural discontinuity. In this case, the formula-based sections of the FFS standard are incapable of evaluating the component without resorting to finite element analysis (FEA). In this paper, an FEA-based technical approach for evaluating FFS assessments using an elastic-plastic material model and reformed criteria is proposed.

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