Crashworthiness optimization of thin-walled tubes using Macro Element Method and Evolutionary Algorithm

In this paper the workflow for obtaining the optimal shape of thin-walled tubes in crashworthiness analysis is presented. The Macro Element Method approach is applied to model large deformations and to calculate crushing parameters of thin-walled sections. The objective of the work is to determine the optimal dimensions of a tube cross-section so as to achieve the maximal energy absorption of the structure. Two optimization algorithms have been developed and coupled with the Visual Crash Studio software that simulates the response of a thin-walled beam during the impact. The first approach applies a modified version of the random search Monte Carlo method. The second is based on Evolutionary Algorithm. Square and hexagonal tubes exposed to axial load are investigated in numerical examples. The best results from both approaches are compared and discussed. The obtained solution is very close to optimal results based on the FEM models and validated by experimental tests. This study illustrates the potential of the optimization in early design stages of the vehicle development process and prepares perspectives for the optimization of complex energy absorbing systems.