Crashworthiness Optimization of an Automotive Frame Based on Gray Relation Theory

A current automotive frame did not absorb energy efficiently during a vehicle frontal crash test. To solve this problem, the finite element model was established. The accuracy of the established model was verified through a real vehicle crash test. Then the orthogonal design of the experiment was conducted. The thicknesses of the outer and inner plates of front anti-collision beams, connecting brackets, and outer and inner plates of front rails were selected as variables. Then the optimum combination of variables was determined by applying gray relational theory. The results showed that the optimized frame can absorb more impact energy than the original design. Maximum deceleration of the lower part of the B-pillar decreased significantly during a frontal crash. Thus the problem of excessive deformation of the rails was solved, and the proposed method can be applied to the optimization of vehicle crashworthiness.