Investigations on the influence of projectile shape on the transient and post impact response of thin sheet structures

摘要

Post-failure observation based analysis of a structure can reveal the information like residual deformations, type, and location of the fracture. But it does not provide the required information completely. Factors like boundary conditions at the impact zone and failure mechanisms remain unresolved. This article presents a combined experimental and numerical approach as an effective tool to examine the transient and post-impact three dimensional full-field response of thin steel plates, when subjected to moderate velocity (100-250 m/s) projectile impact. Experiments were conducted with the help of a single stage gas gun and different projectile shapes in conjunction with 3D DIC (digital image correlation). Finite element (FEM) simulations were also performed to correlate both the transient data and post-impact parameters. Important parameters like the failure modes, plug geometry, out of plane deformations of the steel target plates of two different thicknesses were analysed in detail and reported. Also a comprehensive error measure criterion incorporating both the magnitude error and the phase error was employed to accurately quantify the temporal response. Excellent correlation was observed between the experiments and simulations.