Crashworthiness design optimization of thin-walled cylinders with different inducing grooves

Metal thin-walled cylinders with different inducing grooves were taken as a study object. The maximization of the specific energy absorption (SEA) and the minimization of the maximum peak impact force (Fmax) of the cylinders were chosen as the evaluation indexes and radius of inducing grooves, distance between inducing grooves and free end, and distance between inducing grooves were chosen as design variables to establish a multi-objective optimization model. The finite element code LS-DYNA was adopted to compute the impact responses of the cylinders with different inducing grooves. Furthermore, an approximate objective function was constructed with the radial basis functions (RBFs), the optimal design was performed by using the ideal point method and considering the effects of inducing convex grooves, inducing concave ones and concavo-convex ones on SEA and Fmax. After the optimization, the optimal values of inducing groove radius, diatance between inducing groove and free end, and distance between inducing grooves were obtained. Thus, the ideal and optimal structures for inducing grooves were achieved.