Crashworthiness analysis and design optimization of square aluminum/CFRP hybrid structures under quasi-static axial loading

This work aims to explore crashworthiness of square aluminum/CFRP tubes with different hybrid schemes under quasi-static axial loading condition, and maximize their crashworthiness by performing multi-objective discrete robust optimization design. In the present study, metal/CFRP hybrid tubes with two hybrid schemes and their corresponding individual tubes are manufactured. The crushing process and crashworthiness indictors of all specimens are experimentally investigated under quasi-static axial crushing load. According to the experimental results, the AC hybrid tubes, made of outer aluminum square tube and internally adhered CFRP layers, show excellent energy-absorbing characteristics. Subsequently, numerical simulations are performed for the AC hybrid tubes to further investigate the effects of aluminum wall thickness, CFRP layer number and ply orientation on the energy-absorbing characteristics. It is found that the total energy absorption increases with the increasing tubal wall thickness of aluminum and CFRP layer, and ply orientation makes great contribution to the overall deformation modes and energy-absorbing characteristics of AC hybrid structures. Finally, a multi-objective discrete robust optimization has been conducted to optimize AC hybrid structures for the optimal crashworthy performance.