A two-stage multi-objective optimisation of vehicle crashworthiness under frontal impact


Crashworthiness is one of the most important criteria in vehicle design, which often requires large-scale design analysis for a full-vehicle model consisting of many structural parts and special safety elements. The design typically involves a large number of design variables and sometimes leads to a prohibitively high computing cost. To solve this problem, this paper presents a two-stage procedure to cope with crashworthiness design of a structural frame and occupant restraint system. In the first stage, a multi-objective optimisation is carried out for structural parameters in the frontal parts without considering the details of the occupant restraint device. In the second stage, the parameters of the occupant restraint system are optimised based on an optimised structure system. In these two stages, explicit finite element and multi-body dynamics methods are employed to respectively construct response surface and Kriging model with various designs-of-experiment techniques. A full-scale vehicle model is developed to demonstrate the capability of the present two-stage design method.