Abstract: A finite element simulation model for the tumbling test of a minivan is established, with its reliability verified by the benchmarking on motion attitude, motion parameters and component deformation. According to the test and simulation results of deformation, force and energy absorption of the vehicle, two cross beams of roof and left and right Apillars are determined to be the key structures of target vehicle in rolling collision process. Based on the crashworthiness and energy absorption characteristics of vehicle body, with concurrent considerations of evaluation indicators, i.e. survival space intrusion and structural energy absorption, key structure optimization is completed by using Opt LHD design of experiment, Kriging approximate models, NAGAII multiobjective optimization and proportional coefficient optimization algorithms. After optimization, the total mass of key structures reduces by 2478%, the total energy absorbed by structures lowers by 1881% while the average specific energy absorption for key components increases by 1189%.

Key words: minivan, platform rolling, crashworthiness, multiobjective optimization