Oblique crashworthiness optimization and sensitivity analysis of tapered sandwich columns

In this paper, crashworthiness analysis of a tapered sandwich column under oblique impact loading against a rigid wall is investigated by nonlinear finite element analysis.The energy absorption characteristics of honeycomb sandwich cylindrical columns in oblique crushing process depend greatly on the amount of material which participates in the plastic deformation. The interaction effects between the honeycomb and column walls greatly improve the energy absorption efficiency. The response surface method with cubic basis functions is employed to formulate specific energy absorption and peak crushing force, which reduces considerably the computational cost of crush simulations by finite element method. Based on the results of crash modeling, it is observed that the specific energy absorption has a decreasing trend by increasing the impact angle and decreasing the column thickness. On the other hand, the peek crushing force reduces when the impact angle and the column thickness are increased. Therefore, multiobjective optimization is done to maximize the specific energy absorption and minimize the peek crushing force at the same time. Furthermore, maximizing the specific energy absorption and maximizing impact load angle is performed. Finally, both local and global sensitivity analyses are employed to assess the effect of impact angle and thickness on the specific energy absorption and peak crushing force. The global sensitivity of the specific energy absorption with respect to the impact angle is observed to be more than the column thickness, while the peak crushing force has more global sensitivity to the column thickness compared to the impact angle.