Crashworthiness analysis and optimization of a cutting-style energy absorbing structure for subway vehicles

This study proposes a cutting-style energy absorbing structure to improve the crashing performance of subway vehicles through experiment and numerical simulations. The structure consists of an anti-creeper device, energy absorption tube, cutting knife and clamp. A finite element (FE) model of a cutting-style energy absorbing structure is created and validated by full-scale experimental data. Based on the validated simulation model, the influence of the design parameters, which include the cutting depth (d), the cutting edge angle (CEA) and the chip central angle (CCA), on the impact performance is analyzed. The parametric study found that the design parameters influence the peak cutting force (F-p) and energy absorption (EA). In addition, the structure has prominent advantage in lowering the peak interface force. Finally, the response surface method (RSM) is adopted to achieve maximum EA and minimum F-p simultaneously. The optimized results show that the objectives compete with each other, and the weighting factors are of considerable significance to the most satisfactory Pareto fronts solutions. In this paper, the minimum distance selection method (TMDSM) is adopted to determine the most satisfactory solution. It can be concluded that when CCA = 18.18 degrees, CEA = 23.87 degrees, and d = 2.87 mm, the structure shows the best impact performance and EA = 275.9 kJ and F-p = 887.2 kN.