Design of continuously radial density-graded aluminum foam with unidirectional and bidirectional and study on blast resistance of sandwich tube

This work focuses on investigation of the internal blast resistance of metal sandwich tubes with continuously radial density-graded aluminum foam cores. Based on the 3D-Voronoi technology in polar coordinates, unidirectionally and bidirectionally continuously density-graded aluminum foam were developed for the cores of sandwich tubes in Finite Element (FE) model. And the correctness of core gradient was verified by comparing theoretical design with the actual value generated by FE model. Effects of core density distribution and core density gradient on blast resistance of sandwich tubes were explored and identified. The results indicate that, when the core density gradient is constant, the sandwich tube with negative-gradient core exhibits the smallest maximum deformation of the outer tube, while the negative-middle-low-gradient core tube shows the highest specific energy absorption ( SEA). For negative-gradient core tube, as the core density gradient increases, the maximum deformation of the outer tube decreases significantly, with only slight reduction of the structural SEA. For negative-middle-low-gradient core tube, as the core density gradient increases, the maximum deformation of the outer tube decreases, while the SEA increases.