Crushing behavior and multi-objective optimization on the crashworthiness of sandwich structure with star-shaped tube in the center

A multi-wall structure by sandwiching star-shaped tube between two circulars is proposed and named it CSC-tube in this paper. It is found that the interaction effects between tubes walls play an important role in the improvement of the crashworthiness. The experimental result shows that the mean crushing force of the new design is 25% higher than that of star-shaped tube. The Surrogate model based on radial basis function is employed for the multi-objective optimization problem to maximize the value of the specific energy absorption and minimize the peak value of the crushing force with the design variables-inner, outer and core thickness. The models are optimized by Non-Dominated Sorting Genetic Algorithm-Ⅱ(NSGA-Ⅱ) and the compromise solution shows that 8.03% increase in specific energy absorption and 12.73% decrease in the value of peak crushing force can be achieved.