Characterization of the debris clouds produced by hypervelocity oblique impact of spherical projectiles on honeycomb sandwich shields

The protective capabilities of honeycomb sandwich shields are closely related to their unique core structure. When a projectile obliquely impacts the shield at hypervelocity, the radial multilayer foils can effectively break the projectile through multiple impacts, thereby reducing the impact momentum of the debris on the rear panel and absorbing the main impact energy. In this study, we employed the finite element-smooth particle hydrodynamics adaptive method to replicate experiments on the oblique hypervelocity impacts of spherical projectiles on homogeneous aluminum plates and honeycomb sandwich shields. Based on both the experimental and simulation results, we described the evolution of the debris cloud. In addition, we analyzed the distribution characteristics of the debris cloud and modeled the structural characteristics corresponding to the oblique impacts of spherical projectiles on different protective structures. We also analyzed how the honeycomb core influences the debris cloud during oblique impact to define the failure modes of the front and rear panels as well as the honeycomb core materials. Furthermore, we define the different stages in which damage occurs and examine the response processes for the honeycomb sandwich shields. These findings can serve as a reference for optimizing the design of protective structures.