Crushing analysis and multi-objective optimization of a cutting aluminium tube absorber for railway vehicles under quasi-static loading

To explore a diverse number of energy absorption methods, this paper presents an investigation of a cutting aluminium tube absorber for railway vehicles. A quasi-static cutting experiment on an aluminium tube is conducted. The finite element models presented in this study are based on experimental tests, and good agreement is achieved between the experimental and finite element results. It is shown that the cutting aluminium tube absorber presents a stable deformation mode. The chip morphologies of the numerical simulation and experimental test results are coincident, demonstrating that failure criteria defined under the material model are effective. Moreover, a parametric study is performed using finite element models under quasi-static loading. It is found that the cutting depth t, cutting depth w and cutting angle α have a distinct effect on the energy absorption (EA), mean crushing force (MCF) and peak crushing force (PCF) of the absorber. Sobol' sensitivity analysis is employed to analyze the effects of the design parameters (t, w, and α) on the objective responses (EA and PCF) based on a polynomial response surface model. It is found that at a larger cutting depth, the increases in EA and PCF are larger. Additionally, to optimize the crushing performance of the absorber, a multi-objective optimization is applied to achieve the maximum EA and minimum PCF values. The results show that EA increases with increasing PCF and at the optimal point B (EA = 78.29 kJ, PCF = 341.88 kN), and thus, a balance between EA and PCF is obtained.