Simulation And Body Structural Crashworthiness Research Of Vehicle Frontal Crash

Automotive crash test is the most accurate and reliable method in the vehicle safety research. The automotive crashworthiness is verified by the real vehicle crash test. But this kind of test is destructive, it often needs to repeatedly perform crash test in order to get a design goal, it is quite expensive and it has a long preparation period, therefore it becomes an inevitable trend of automotive safety research that guides and replaces a part of test work by the car crash simulation. Through the simulation calculation, we can economically and effectively provide some basic rules and directions for the car design or improvement process, avoid a mass of trial work, it can reduce the developmental cost and shorten the developmental period.The crash safety research which runs through the whole development process of vehicle. In order to ensure the passengers’ safety when there is an accident, it mainly depends on the body’s resistance ability to deformation, crashworthiness and the corresponding safety measures(such as body strength, energy absorption structure, internal facilities strength, seat belts, escape exits and so on) to improve its safety performance. Improving the automotive energy absorption structure, body strength, energy transmission path and vehicle’s crashworthiness reasonably is a very important approach, that is body structure safety research.This paper selects a car as the study object, first of all, according to its 3D data model and the basic technical data, using Hypermesh to establish a vehicle frontal crash simulation system, and utilizing LS-DYNA solver to calculate the finite element simulation system; secondly, comparing the basic energy curve comes from the above result with the body deformation modes in the process of collision, verifying the accuracy and reliability of the simulation model. Besides, combining with the evaluation standard of automobile crash regulations, analyzing and evaluating the important indicators of front rigid wall collision, such as B-pillar bottom acceleration, the deformation of vehicle or key structure, force transfer influence, investigating the car’s collision safety performance; on the basis of the collision simulation result, describing the control ideas of various response indicators, identifying the weaknesses of front energy absorption area, independently analyzing the bending causes of front longitudinal beam and proposing the optimization scheme to control the deformation mode. What’s more, according to the elastic-plastic mechanical analysis, studying the stability and energy absorption of front rail in the process of collision, and on this basis, using the genetic algorithm to optimize the structure parameters again in order to improve its energy absorption and stability. Through the two optimizations, transferring the front girder’s bending deformation pattern to crush deformation, and improving its energy absorption, reducing the acceleration peak of B-pillar bottom, improving the collision safety performance of the vehicle, achieving the desired goal.In this paper, the simulation calculation results of the car’s finite element model in accordance with the basic rules of the vehicle crash simulation. Applying the computer simulation, genetic algorithm to solve the engineering optimization problem, providing the references for the crashworthiness research and optimization study of the body structure.