Multi-objective crashworthiness design optimisation of thin-walled tubes

Abstract

Thin-walled structural members contribute significantly to the ability of an automobile body to absorb energy during frontal impact. The objective of this paper is to improve the energy absorption performance of crash tubes that are placed behind the bumper in automotive vehicles using shape and size optimisation. The best cross section is determined initially, and then dynamic axial crushing simulation is carried out on thin-walled octagonal tube, which has crush initiators. In order to maximise the absorbed energy, shape and size, optimisation techniques are applied using a response surface approximation technique. The design of experiment method is employed to construct the response surfaces. An explicit finite element code, LS-DYNA, was used to implement the parallel computations.