Multi-objective crashworthiness optimization of CFRP/Al hybrid tube under transverse loading

This paper aimed to investigate the bending collapse and optimization of carbon fiber reinforced plastics/aluminum (CFRP/Al) hybrid tubes with different parameters through the three-point bending test. Based on the experimental tests, the transverse energy absorption of upon hybrid tubes was found to be higher than net aluminum tube, and the overall strain and internal failure mode of the CFRP/Al hybrid tube were observed by digital image correlation technology and X-ray computed tomography scan. The failure of outer CFRP and interaction between aluminum and CFRP was the main factor to improve loading capacity and energy absorption, and various parameters configuration of CFRP and aluminum are of their own benefits. Afterward, the validated numerical simulation model was carried out by correlating with the test results. Based upon the numerical simulation model, the parametric study and design optimization on the CFRP/Al hybrid tube (concerning the thickness of aluminum, ply angle, and layer number of CFRP) were further conducted systemically. It was found that the optimization results were θ = 15°, t = 1.65 mm, n = 3, which decreased the peak force ( F max ) by 10.82%, mass is reduced by 13.0%, and specific energy absorption ( SEA) shows almost no change.