Abstract:In this paper, the dynamic response of continuously density-graded aluminum foam sandwich tubes under internal explosion load was studied. The finite element model of the continuously density-graded aluminum foam and sandwich tubes was established in polar coordinates by 3D-Voronoi technology. The influences of the core density distribution, such as positive-gradient, negative-gradient, and V-shaped gradient including high in middle and low at both ends (middle-high-gradient), low in middle and high at both ends (middle-low-gradient), core density gradient, the assembly method of the tube wall and core, and length-to-diameter ratio of explosives on the antiknock performance of the sandwich tube structure were analyzed. The results demonstrate that when the core density gradient is the same, the maximum deformation of the outer tube in the sandwich tube with a negative-gradient core is the smallest, the sandwich tube with a middle-low-gradient core has the highest specific energy absorption, and the antiknock performance of the sandwich tube with a middle-high-gradient core is the worst. As the core density gradient increases, the maximum deformation of the outer tube in the sandwich tube with a negative-gradient core significantly decreases. The specific energy absorption of the sandwich tube with a middle-low-gradient core shows a trend of first increasing and then decreasing, while the anti-explosion performance of the sandwich tube with a middle-high-gradient core weakens. The ideal bonding between the tube walls and the core effectively improves the specific energy absorption of sandwich tubes with a uniform, negative-gradient, or middle-low-gradient core, but it also increases the maximum deformation of the outer tube. Under different length-to-diameter ratio of explosives, the maximum deformation of the outer tube in the sandwich tube with a negative-gradient core is smaller. The present work is expected to provide some insights for researchers and engineers to design such structures for protective engineering applications.