Crashworthiness of nested corrugation square energy-absorbing tubes with circumferentially cosine profile.

With the development of railway technology, high-speed trains have been invested in practical operation increasingly. The traffic accident that train runs at high speed will cause casualties and property losses. The energy absorption tube can effectively alleviate the damage of the vehicle in the collision process and protect passengers in the buffering process. In this paper, nested corrugation square energy-absorbing tubes (NCSTs) with circumferentially cosine profile and different inner structures are analyzed by adopting finite element (FE) simulation. The quasi-static compression tests and proposed theoretical model based on Simplified Super Folding Element (SSFE) theory are employed to validate the effectiveness of numerical models. The simulation results indicates that the crushing modes possess certain sensitiveness to cross-sectional conformation and the NCSTs present more stable and orderly deformation modes compared with non-nested tubes. The specific energy absorption (SEA) and crushing force efficiency (CFE) of NCST can be increased by 52.49 and 19.07% compared to ordinary corrugation tube, respectively. In addition, the tube with two-layers octagonal wall (SO1D) is selected as optimal structure because it is ranked first under cases of 40% by adopting the technique for order preference by similarity to ideal solution (TOPSIS) method. Finally, the sensitivity analyses based on SO1D are conducted. The results show that the parametric variation of trib and tout fairly effect on the deformation pattern. And increases in wall thickness t and section size of the middle wall Dmid will all result to increases in initial peak crushing force (IPCF) and significant variation on other crashworthiness criteria. This paper offers certain reference significance for the study of energy-absorbing structures. [ABSTRACT FROM AUTHOR]