Dynamic response and energy absorption performance of aluminum foam-filled sandwich circular tubes under internal blast loading

•A theoretical model is established to predict the internal blast response of foam-filled sandwich circular tubes by considering the circumferential plastic membrane force and axial moment components.•A 3D finite element model of the foam core based on a Voronoi algorithm is established to simulate the deformation of foam-filled sandwich circular tubes under internal blast loading.•The influence of an axially graded distribution of the foam core on the energy absorption performance of foam-filled tubes is revealed.