Impact perforation of sandwich panels with graded hollow sphere cores: Numerical and Analytical investigations

In this study, we numerically and analytically investigate the impact perforation of sandwich panels made 0.8 mm 2024-T3 aluminum alloy skin sheets graded polymeric hollow sphere cores with four different gradient profiles. A suitable numerical model was conducted using LS-DYNA code, calibrated an inverse test, instrumented a Hopkinson bar, validated experimental data from literature. Moreover, effect boundary conditions on resistance studied core discussed. The simulation results showed that piercing force– displacement response is affected by density Besides, energy absorption capability can be effectively enhanced modifying arrangement layers un-clumping in panel, which rather too hard to achieve clumping conditions. Finally, analytical model, taken account only quasi-static plateau stress, developed predict top pic peak load panel.