Computational simulation of impact perforation of polymeric-foam core sandwiched composites with different skin–face configurations

The normal and oblique impact perforation responses of composite sandwich panels based on a Rohacell polymeric-foam core are numerically investigated at high impact energies (>60 J). A cylindrical form factor with a diameter of 140 mm and a thickness of 15 mm is selected for the sandwich specimens. Four different stacking sequences of 1 mm carbon/epoxy face sheets are considered (i.e., quasi-isotropic, cross-ply, angle-ply, and unidirectional stacking). A computational model was constructed using LS-DYNA finite element software and an inverse perforation testing scheme adapted with a split Hopkinson bar and confirmed by comparing these results with those obtained using the free shooting projectile-target testing schemes published in the literature. The effects of impact energy, failure modes, impact angles, and damage key parameters are analyzed. The results reveal the contact force versus displacement curves are highly influenced by the impact energy increases. The stacking sequence of the face sheets does not influence the energy absorption capacity. However, the maximum absorbed energy increases with an increasing impact angle up to 20°. Using Hopkinson bars in conjunction with the virtual inverse perforation testing approach is effective for examining the response of sandwich composites at high impact energies.