Crashworthiness and optimization design of quadruple-cell Aluminum/CFRP hybrid tubes under transverse bending

This paper aims to investigate the bending collapse and crashworthiness of the quadruple-cell Al/CFRP (aluminum/carbon fiber reinforced plastic) hybrid tubes under quasi-static and dynamic loading. Three-point bending tests were first conducted for pure Al tubes and Al/CFRP hybrid tubes with different wrapping angles. Experimental results showed that the enhancement effect of CFRP wrapping on energy absorption efficiency of hybrid structures was affected by several factors. Numerical analyses were then carried out by ABAQUS/Explicit, and good agreements were achieved between the simulation and experimental results. The validated numerical model was further employed to investigate the effects of the partial wrapping, wrapping angle and ply thickness on the crashworthiness of Al/CFRP hybrid tubes. Results showed that the increase of wrapping angle and ply thickness could enhance the bending resistance and delay or avoid the fracture of CFRP in the bottom flange. The Al/CFRP tube with appropriate partial wrapping could achieve 7.9% higher specific energy absorption (SEA) than the entirely wrapped counterpart. In addition, the sequential response surface method (SRSM) was adopted to optimize the structural parameters and to further improve the crashworthiness of the hybrid tubes. The SEA of the Al/CFRP tube was increased by up to 30.3% by the RSM optimization.