Failure behavior and regularity analysis of aluminum panel subjected to high-velocity sandstone impact

Sandstone impact, a common phenomenon occurred during takeoff and landing of aircraft, can cause significant damage to aircraft structures and even endanger flight safety, which highlights the failure behavior of aircraft structures subjected to sandstone impact as an essential issue for the impact-resistant design. This paper aims to investigate the failure behavior of aluminum panel impacted by sandstone and conduct regularity analysis. High-velocity impact tests of sandstone on aluminum panel were performed with various sandstone shapes, masses, and velocities. A finite element model was developed by incorporating the rate-dependent constitutive model for sandstone. The results show that the sandstone failure comprises the initial longitudinal cracks and subsequent fragmentation process, similar to the early dynamic compressive failure of sandstone loaded by Hopkinson bar and the disintegration behavior of bird and hail impact, respectively. The sandstone shape shows a negligible influence on the deformation response of aluminum panel, and exhibits different effects on energy absorption characteristic at different impact velocity. The deformation response of aluminum panel is affected by sandstone mass, which also causes different energy absorption characteristic at low impact velocity. As the impact angle of sandstone increases from 0° to 15°, both the maximum strain and impact force exhibit a downward trend, and contradictory tendency is observed for the maximum displacement and stress, residual velocity, kinetic energy and mass of sandstone as well as energy absorption characteristic.