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

The dynamic response and energy absorption properties of an aluminum foam-filled sandwich circular tube under internal blast loading is investigated by experimental, theoretical, and numerical simulations. A series of blast experiments were performed using spherical emulsion explosives of different masses. Three axially deformed regions are obtained for the internal and external tubes: a region with large plastic deformation, a rigid section moving around the plastic hinge, and an undistorted boundary region. Explosive mass, the internal and external tube wall thickness have a significant influence on the final deformation of a foam-filled sandwich circular tube. A theoretical explicit calculation method including the circumferential plastic membrane forces and the axial moment components has been developed to predict the internal blast response of a foam-filled sandwich circular tube. The FE model, based on a 3D Voronoi algorithm for the foam core, was developed to investigate the deformation mechanism of a foam-filled sandwich circular tube. Both numerical and experi-mental results are consistent with the theoretical predictions. In addition, the impact of the explosive mass, the diameter and the wall thickness of the internal and external tubes, and the axial arrangement of the core on the dynamic response and energy absorption properties are investigated. It is found that the sandwich circular tube with negative gradient core has the best anti-blasting performance among the sandwich circular tubes with gradient arrangement.