Crashworthiness optimization of a sandwich tube filled with CFRP sinusoidal corrugated board

Abstract

Composite thin-walled structures play a critical role in the passive energy absorption of vehicles. This paper proposes a design method of a sandwich tube filled with a sinusoidal corrugated board (SCB). The geometric parameters of the core are designed by the amplitude A, and the period N of the sine function. The variation range of A is 5-9 and that of N is 1-5, with intervals of one. Among them, a group of regular hexagonal sandwich tubes (RHST) with A=9 and N=3 were fabricated to explore their energy absorption characteristics. The results show that the deformation modes in the finite element simulations and the experimental results are extremely consistent, and the maximum errors of specific energy absorption (SEA) and peak impact force (PCF) are 4.15% and 1.84%, respectively. In addition, SEA and PCF theoretical models were established to reveal the coupling between CFRP tube and AL tube, and the error was 9.48% and 4.78%, respectively. The energy absorption properties of the sandwich tube are revealed by comparing different profiles, number of layers, angles and sinusoidal parameters. It was found that the deflection of the radial peaks and troughs reduces the axial energy absorption capacity of the sandwich tube. Finally, RHST is optimized using weight matrix analysis based on the orthogonal experimental design. Compared to the original structure, the optimized sandwich tube increases the SEA and SEAcouple by 38.67% and 106.37%, respectively, while decreasing the PCF and PCF couple by 4.43% and 28.57%, respectively. The energy absorption properties of the optimized structure show advantages over the original design.