Modeling and multi-objective optimization of a bionic crash box with folding deformation

Traditional crash box is unable to efficiently solve the problem of bending deformation during the collision process, which limits the energy absorption performance and crashworthiness. This paper introduces the structure of cactus into the design of crash box and attempts to redesign a new one with stable folding deformation. By imitating the cactus characteristic, the bionic crash box consists of two parts: one is the corrugated angular structure, and the other is its thickness functionally gradient distribution along the axial direction. Based on the sensitivity analysis, the parameters which have great influences on the energy absorption performance are selected as the design variables. The multi-objective optimization design is conducted based on response surface model and Latin hypercube design of experiment. Simulation results show that the bionic crash box can effectively weaken the damage to the autobody and improve the energy absorption performance through stable folding deformation.