Bending analysis and design optimisation of tailor-rolled blank thin-walled structures with top-hat sections

摘要

The purpose of this paper is to provide efficient lightweight design for improving the loading carrying efficiency and energy absorption capability of tailor-rolled blank thin-walled structure with top-hat section (TRB-TH) under transverse loading. First, a new finite-element (FE) modelling method for the TRB-TH structure is proposed. The FE model is validated by performing quasi-static bending tests on two kinds of typical specimens. Second, the validated FE model is used to study the loading carrying efficiency and energy absorption capability of TRB-TH structures with variations in the thicknesses of constant thickness zone, lengths and positions of thickness transition zone by using global sensitivity analysis. Finally, to determine the optimal thickness distribution, multiobjective optimisation design is performed by integrating response surface method and non-dominated sorting genetic algorithm (NSGA-II) algorithm. The results have demonstrated that the TRB-TH structures can not only produce much better Pareto solutions than the traditional designed uniform thickness (UF-TH) counterparts, but also provide a better balance between lightweight and crashworthiness of energy absorbers simultaneously. The proposed approach can provide some useful guidance for designing the TRB-TH energy absorbers of vehicle body.