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

¹ Laboratoire de Génie Mécanique, Ecole Nationale d’Ingénieurs de Monastir, University of Monastir, Av. Ibn ElJazzar, Monastir - 5019, Tunisia
² Faculty of Engineering, University of Tabuk, P.O. Box 741, Kingdom of Saudi Arabia

^* Corresponding author: ibrahim.nasri@issig.rnu.tn

Published online: 9 September 2021

Abstract

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