Experimental and numerical study on energy absorption performance of CFRP/aluminum hybrid square tubes under axial loading

Metal/composite hybrid square tubes that combine the advantages of low-density of composite with low-cost of metal provide a potential energy absorption device for automobiles. The axial crushing performance of CFRP/ aluminum hybrid square tubes wrapped with single angle-ply and antisymmetric angle-ply was studied by experimental and numerical methods. Results show that for tubes wrapped with single angle-ply [0] 4 or [45]4, crack propagation occurred and the CFRP separated from aluminum, which resulted in worse energy absorption capacity than pure aluminum tube. A stable symmetric deformation was observed in hybrid square tubes wrapped with antisymmetric angle-ply. The specific energy absorption (SEA) for those tubes was improved 11% and they showed better energy absorption performance compared to pure aluminum tube. Then, the effect of thickness of tubes, including hybrid square tubes with identical aluminum and hybrid square tubes with identical mass, on the energy absorption capacity was further investigated by simulation. It was found that only when the number of CFRP layer reaches a certain value, hybrid square tubes perform better than pure aluminum tube with identical mass in energy absorption. Moreover, influence of mass of the tube, and substituting aluminum alloy with CFRP on the energy absorption of hybrid square tubes with identical aluminum and different number of CFRP layers was studied.