Topological optimization of the automobile bumper design under impact from the passive safety standpoint

Abstract

Topological optimization of the elements of the automobile's design helps to reduce its weight while maintaining the strength and rigidity characteristics, therefore, the use of optimization in the design process is an important and urgent task. In this paper, topological optimization of the vehicle bumper is considered from the standpoint of passive safety. Brief theoretical information on the optimization method based on application of the method of hybrid cells and the concept of a body of variable density is given. The article presents the developed rational finite element models of the bumper and impactor for topological optimization, the loading scheme is described, the results with acceptable accuracy and minimum solution time using the LS-DYNA solver and the LS-TaSC module are obtained. The selection of the type and size of the finite elements for the solution of the problem of the shock interaction of the bumper and the impactor is substantiated by the example of three models of different degree of structuring. The variants of the initial and boundary conditions for topological optimization are considered. The substantiation of a choice of time of the decision of a problem of impact influence from the point of view of rational use of computer time and accuracy of received results is given. A variant of the design of the bumper and its finite element model is presented after the completion of the optimization results, and a check is made that the modified model satisfies the initial requirements. As a result, the weight of the modified bumper structure was 29% less than the original, while maintaining the stiffness and energy intensity parameters.