On the Evaluation of “Nhtsa” Automotive Fe Model in Head on Crash Using Ansys Ls-Dyna System Against “Iihs” Test.

Abstract

Simulations of automotive crash are now a well-established instrument for ensuring occupants safety at most types of crash scenarios and improving the car design accordingly when needed. Many Automotive crash simulation's systems are available currently, where each system strives to attain ease of use, high accuracy, and consuming the least possible computer time in running the crash scenario. However, most of these systems are used independently. A unique exception of these systems is ANSYS LS-DYNAYwhere the two systems can be used as one unit in ANSYS explicit module, where one can combine the ease of use of ANSYS with the world class suite of LS-DYNA.This system is quite straightforward to modify the car model, change elements attributes, redefine the elements integration rule, and spotweld definitions to achieve less running time while keeping almost the same accuracy. This paper presents an evaluation of a modified National Highway Traffic Safety Administration (NHTSA) finite element model of Ford truck structure.The model structure is first imported to ANSYS LS-DYNA simulation system to facilitate its handling, modification, and applying different simulation scenarios. Then after modification, it is evaluated through the following three steps: first, evaluated against the ability to rollover almost free of stresses, second, evaluated in a head on crash test at low speeds such as 5 miles/hours.This scenario can happen while moving out of the drive way or in a parking lot area, and third, evaluated in a head on crash test against rigid fixed barrier with 35 miles/hour test simulating the Insurance institute for highway safety (IIHS) test. The results show that the modified model is quite capable of capturing the main characteristics of the three tests adequately.