Energy absorption behaviour of an aluminium foam-filled circular-triangular nested tube energy absorber under impact loading

A novel aluminium foam-filled circular-triangular nested tube (AFCTNT) energy absorber was developed in this study, and its energy absorption behaviour under impact loading was experimentally and numerically studied. Drop-weight impact tests on the AFCTNT energy absorbers with different volumes of aluminium foam filler were first conducted to obtain their energy absorption parameters, force–displacement responses, and deformation modes. In addition, numerical studies on AFCTNT energy absorbers were also carried out, and the specific energy absorption of nested tubes and aluminium foam were obtained to further reveal their energy absorption performances. Experimental results indicated that the deformation modes of AFCTNT energy absorbers were evidently affected by the volume of aluminium foam filler. Moreover, the energy absorption performances of AFCTNT energy absorbers were found to be significantly improved by filling aluminium foam in terms of higher energy absorption, specific energy absorption, mean crushing force, and crushing force efficiency. Both experimental and numerical results demonstrated that the AFCTNT energy absorber with fully-filled aluminium foam outperformed the other AFCTNT energy absorbers owing to more significant interaction effect between the nested tubes and aluminium foam.