Soft-Computing-Based Car Body Deformation and EES Determination for Car Crash Analysis Systems

Car body deformation modeling plays a very important role in crash accident analyses, as well as in safe car body design. The determination of the energy absorbed by the deformation and the corresponding energy equivalent speed can be of key importance; however, their precise determination is a very difficult task. Starting from the results of crash tests, intelligent and soft methods offer a way to model the crash process itself, as well as to determine the absorbed energy, the before-crash speed of the car, etc. In this paper, a modeling technique and an intelligent expert system are introduced, which, together, are able to follow the deformation process of car bodies in car crashes and analyze the strength of the different parts, which can significantly contribute to the improvement of the safety of car bodies.

I. Introduction

Crash and catastrophe analysis has been a rather seldom discussed field of traditional engineering in the past. In recent time, both the research and theoretical analyses have become part of the everyday planning work [1]–[3]. The most interesting point in crash analysis is that, although the crash situations are random probability variables, the deterministic view plays an important role in them. The stochastic view, statistical analysis, and frequency testing all concern past accidents. Crash situations, which occur the most frequently (e.g., the characteristic features of the crash partner, the direction of the impact, and the before-crash speed) are chosen from these statistics and are used as initial parameters of crash tests. These tests are quite expensive; thus, only some hundred tests per factory are realized annually, which is not a sufficient amount for accident safety. For the construction of optimal car body structures, more crash tests are needed. Therefore, real-life tests are supplemented by computer-based simulations, which increase the number of analyzed cases to 1000–2000. The computer-based simulations—like the tests—are limited to precisely defined deterministic cases. The statistics are used for the strategy planning of the analysis. The aforementioned example clearly shows that the stochastic view does not exclude the deterministic methods [4], [5].