Spot Weld Failure Prediction and Simulation in Crash Analysis

2004 ◽  
Author(s):  
Xiaodong Tang
Keyword(s):  
Major Effect ◽  
Spot Weld ◽  
Vehicle Body ◽  
Design Parameters ◽  
Test Results ◽  
Crash Analysis ◽  
Spring Element ◽  
Weld Failure ◽  
Projection Equations ◽  
Prediction And Simulation

Weld failure/separation in vehicle body structures subjected to impact condition may results in component instability and thus reduced energy absorption. A new finite element method has been developed for modeling the behavior of spot welds in elastic, plastic and separation stages. This method can be used to simulate weld failure in vehicle crash analysis using a failure formulation derived from coupon test results. It is a generalized method and is intended to be applicable to any combination of the weld design parameters such as thickness, materials, coating and impact speed. The method has been validated on the crash tests on straight and S-type rails with a hat section. The CAE prediction based on the modeling procedure correlates well with the test results for all the rail crush cases. The welds are modeled using the beam-type spring element with the newly developed weld damage parameters. The baseline curves for the spring element and the detailed projection equations developed are provided in this paper. The presented method and major effect curves from the testing can also benefit the spot weld design and specification development.

Crashworthiness of a Truck Cabin using Finite Element Simulation

2017 ◽  
Vol 8 (4) ◽  
Author(s):  
N.K. Mishra ◽  
S.K. Pradhan.
Keyword(s):  
Finite Element ◽  
Rigid Wall ◽  
Vehicle Body ◽  
Design Parameters ◽  
Crash Test ◽  
Small Scale ◽  
Scale Production ◽  
Crash Analysis ◽  
Structural Behaviour ◽  
Crash Simulation

A crash test is a form of destructive testing in order to ensure safe design in case of an impact or collision. These impact tests are carried out to understand a components structural behaviour and its response under different collision conditions. But it is not always economical to destroy a specimen to ensure its safety, especially in case of small scale production. Moreover actual crash testing in different conditions requires high resources and time. Crash simulation is very popular now a days because it is a virtual representation of a destructive crash test of a vehicle using a computer simulation in order to examine the level of safety of the vehicle and its occupants in different conditions like collision velocity, collision direction, colliding object, material and number of component of colliding object etc and hence saves the time and cost. Data obtained from a crash simulation indicate the capability of the vehicle body to protect the vehicle occupants during a collision against injury. In this study a FE crash analysis of commercial truck cabin in two different cases (Bare cabin and loaded cabin) using Finite Element Approach (FEA) is focused. Crash analysis of truck cab is performed using FEA in order to predict the design parameters for minimization harm to the occupants of the vehicle. A bare truck cabin and a rigid wall were used to simulate crash conditions with different crashing velocity and impact angles. CATIA V5R20 CAD software is used for the modeling of the selected cabin components followed by FE meshing through Hypermesh and then analysis is done using LS-DYNA by setting the boundary conditions, material properties etc. appropriately.

Estimation of Seismic Energy Dissipation for Steel Slit Shear Walls Considering Out-of-Plane Buckling

2021 ◽  
Author(s):  
Yiming Ma ◽  
Liusheng He ◽  
Ming Li
Keyword(s):  
Energy Dissipation ◽  
Shear Walls ◽  
Seismic Energy ◽  
Thickness Ratio ◽  
Design Parameters ◽  
Test Results ◽  
Loading Test ◽  
Aspect Ratios ◽  
Out Of Plane ◽  
Energy Dissipation Capacity

Steel slit shear walls (SSSWs), made by cutting slits in steel plates, are increasingly adopted in seismic design of buildings for energy dissipation. This paper estimates the seismic energy dissipation capacity of SSSWs considering out-of-plane buckling. In the experimental study, three SSSW specimens were designed with different width-thickness ratios and aspect ratios and tested under quasi-static cyclic loading. Test results showed that the width-thickness ratio of the links dominated the occurrence of out-of-plane buckling, which produced pinching in the hysteresis and thus reduced the energy dissipation capacity. Out-of-plane buckling occurred earlier for the links with a larger width-thickness ratio, and vice versa. Refined finite element model was built for the SSSW specimens, and validated by the test results. The concept of average pinching parameter was proposed to quantify the degree of pinching in the hysteresis. Through the parametric analysis, an equation was derived to estimate the average pinching parameter of the SSSWs with different design parameters. A new method for estimating the energy dissipation of the SSSWs considering out-of-plane buckling was proposed, by which the predicted energy dissipation agreed well with the test results.

Spot Weld Failure Prediction in Safety Simulations Using MAT-240 Material Model in LS-DYNA

2015 ◽  
Author(s):  
Sivaprasad Koralla ◽  
Ganesh Bhagwant Gadekar ◽  
V Ramana Pavan Nadella ◽  
Susanta Dey
Keyword(s):  
Failure Prediction ◽  
Material Model ◽  
Spot Weld ◽  
Weld Failure

The Surface Roughness Effect on the Dynamic Stiffness and Damping Characteristics of the Hydrostatic Thrust Spherical Bearings: Part 5 of 5 — Clearance Type of Bearings

2007 ◽  
Author(s):  
Ahmad W. Yacout
Keyword(s):  
Surface Roughness ◽  
Capillary Tube ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Major Effect ◽  
Design Parameters ◽  
Compressibility Effect ◽  
Damping Coefficients ◽  
Stiffness And Damping ◽  
Fluid Compressibility

This study has theoretically analyzed the surface roughness, centripetal inertia and recess volume fluid compressibility effects on the dynamic behavior of a restrictor compensated hydrostatic thrust spherical clearance type of bearing. The stochastic Reynolds equation, with centripetal inertia effect, and the recess flow continuity equation with recess volume fluid compressibility effect have been derived to take into account the presence of roughness on the bearing surfaces. On the basis of a small perturbations method, the dynamic stiffness and damping coefficients have been evaluated. In addition to the usual bearing design parameters the results for the dynamic stiffness and damping coefficients have been calculated for various frequencies of vibrations or squeeze parameter (frequency parameter) and recess volume fluid compressibility parameter. The study shows that both of the surface roughness and the centripetal inertia have slight effects on the stiffness coefficient and remarkable effects on the damping coefficient while the recess volume fluid compressibility parameter has the major effect on the bearing dynamic characteristics. The cross dynamic stiffness showed the bearing self-aligning property and the ability to oppose whirl movements. The orifice restrictor showed better dynamic performance than that of the capillary tube.

The Mechanism and Solution of Harmonic Gear Whine Noise in Automotive Transmission Systems

2007 ◽  
Author(s):  
Jaegon Yoo ◽  
Koo-Tae Kang ◽  
Jin-Wook Huh ◽  
Chimahn Choi
Keyword(s):  
Surface Structure ◽  
Design Parameters ◽  
Test Results ◽  
Gear Noise ◽  
Transfer Path ◽  
Gear Design ◽  
Automotive Transmission ◽  
Wave Patterns ◽  
Tooth Modification ◽  
Harmonic Noise

Since gear noise in automotive is one of the most unpleasant noises for passengers, various solutions, such as gear design optimization, tooth modification and transfer path reformations in the vehicle have been developed. But, these attempts are mainly focused on the fundamental mesh excitation of the gear set without any consideration of their harmonic noise (1st, 2nd or higher). Harmonic gear whine noise is easily audible in the vehicle because of their high frequency characteristics in spite of low sound pressure level. This annoying pure-tone noise is usually issued in the transmission system composed of the gears produced by grinding process. This paper will present the main sources of this harmonic gear whine noise with the test results of gears with identical design parameters but having different surface structure (roughness parameters, wave patterns). Additionally, manufacturing guidelines of gear surface structure will be proposed at the end of this paper.

Vehicle Body and Roll Cage Assessment involving Frontal, Side and Roll-over Crash Analysis by FEA using LS-Dyna

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
V. Hariram ◽  
K. Venkatesh ◽  
M. Venkata Saidev ◽  
M. Surisetty Mahesh ◽  
M. Vinothkumar ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Structural Steel ◽  
Three Dimensional ◽  
The Body ◽  
Vehicle Body ◽  
Crash Analysis ◽  
Steel Members ◽  
Vehicle Collision ◽  
Six Degree Of Freedom ◽  
Frontal Side

Simulating the vehicle collision has gained importance in the automotive sector due to its accuracy, cost effectiveness and enhanced reliability. It aids in improving the safety of driver and passenger and also examine the cause of crash or collision. This numerical analysis investigates the materials capability to enhance safety. A three-dimensional vehicle model was developed along with its roll cage using solid work tool. Hypermesh work bench was employed to discretise the sensitive parts of the body and roll cage using beam 189 element having six degree of freedom at each node. The existing structural steel members were replaced with reinforced carbon fibre in all the sensitive part of the body and roll cage and its structural stability was assessed using the frontal, side and roll over crash simulation using LS Dyna. This investigation also reveals the change in internal energy, kinetic energy absorption and momentum transfer for both structural steel and carbon fiber under all the crash scenarios. The outcomes of this numerical investigation proved that the reinforced carbon fiber can be effectively replaced with the structural steel to enhance safety.

Paper 8: Small Computer Procedures as Tools for Structural Designers

1969 ◽  
Vol 184 (13) ◽  
pp. 62-70
Author(s):  
G. A. Wardill
Keyword(s):  
Structural Design ◽  
Design Tool ◽  
Vehicle Body ◽  
Small Computer ◽  
Test Results ◽  
Data Preparation ◽  
Processing Times ◽  
Beam Mode

The system of simplified computer procedures described is intended as a basic structural design tool for designers and draughtsmen. An example is given of how to estimate the beam-mode deflection of a production vehicle body. The degree of accuracy obtained is shown by comparison with rig test results. Data preparation and processing times are also discussed.

A Novel Active Suspension System for Automotive Application

1994 ◽  
Vol 208 (4) ◽  
pp. 243-250 ◽  
Author(s):  
N J Leighton ◽  
J Pullen
Keyword(s):  
Computer Simulation ◽  
Active Suspension ◽  
Input Power ◽  
Suspension System ◽  
Automotive Application ◽  
Test Results ◽  
Active System ◽  
Spring Element

This paper describes a novel type of active suspension based on a buckling spring element installed in an actively controlled variable leverage system. The development of the suspension system through stages of computer simulation, implementation and test is outlined, together with the test results. The suspension system does not fall into any of the established categories of active system but may be seen as fitting into a recently identified category of variably leverage systems. The system is shown to be capable of controlling a vehicle body's motion while providing excellent road input isolation and requiring input power levels of below 150 watts per wheel.

scholarly journals Predicting the Onset of Cavitation in Automotive Torque Converters—Part II: A Generalized Model

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
D. L. Robinette ◽  
J. M. Schweitzer ◽  
D. G. Maddock ◽  
C. L. Anderson ◽  
J. R. Blough ◽  
...  
Keyword(s):  
Dimensional Analysis ◽  
Torque Converter ◽  
Fundamental Principle ◽  
Empirical Models ◽  
Operating Conditions ◽  
Design Parameters ◽  
Test Results ◽  
Linear Regression Technique ◽  
Torque Converters ◽  
Onset Of Cavitation

The objective of this investigation was to develop a dimensionless model for predicting the onset of cavitation in torque converters applicable to general converter designs. Dimensional analysis was applied to test results from a matrix of torque converters that ranged from populations comprised of strict geometric similitude to those with more relaxed similarities onto inclusion of all the torque converters tested. Stator torque thresholds at the onset of cavitation for the stall operating condition were experimentally determined with a dynamometer test cell using nearfield acoustical measurements. Cavitation torques, design parameters, and operating conditions were resolved into a set of dimensionless quantities for use in the development of dimensionless empirical models. A systematic relaxation of the fundamental principle of dimensional analysis, geometric similitude, was undertaken to present empirical models applicable to torque converter designs of increasingly diverse design parameters. A stepwise linear regression technique coupled with response surface methodology was utilized to produce an empirical model capable of predicting stator torque at the onset of cavitation with less than 7% error for general automotive torque converter designs.

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