Crashworthiness study on circular hybrid corrugated tubes under axial impacts

Thin-walled structures are universally used as energy-absorption devices for their great crashworthiness characteristics and light weight. In this paper, a novel tubular configuration is introduced with a gradually decreasing amplitude of the corrugation profile in the axial direction, namely, a hybrid corrugated tube (HCT), to improve the energy-absorption capacities of ordinary corrugated tubes (OCTs). Based on the validated finite element (FE) models, the effects of geometric parameters of the HCTs on crashworthiness are investigated. The numerical results show the HCTs exhibit advantages on the energy absorption capability compared to OCTs, and the crashworthiness indicators and deformation modes of the HCTs depend strongly on the wavelength and constant corrugation ratio. The strengths of the HCTs gradually increases as the compression progresses, and when the constant corrugation ratio increases, the strengthening effect gradually weakens. By comparing OCTs and HCTs with the same wavelengths and deformation modes, it can be found that in the HCTs, the SEA values increase by 21%-57%, the F-m values increase by 15%-45%. The lower is the constant corrugation ratio, the more obvious are the increase in the EA, SEA, F-m values. Finally, a multi-objective optimization is conducted to obtain the optimized HCT configuration for maximizing the SEA and minimizing the F-max. The optimal HCTs are of even more superior crashworthiness and great potential as an energy absorber.