High-velocity impact response of fiber metal laminates: Experimental investigation of projectile's deformability

Abstract

The aim of this research is to investigate the influence of projectile's deformability on ballistic impact response of fiber metal laminates. High-velocity impact experiments have been carried out via a light gas gun setup using rigid, semi-rigid and deformable projectiles with the same diameter, nose shape and mass. Fiber metal laminates have been made of two identical aluminum facing plates and different number of glass/epoxy composite plies in the middle. Several local and global mechanisms for kinetic energy absorption of projectiles have been detailed and ballistic limit velocity, as well as specific perforating energy for all cases have been determined. The results indicated that by increasing the deformability of the projectile, the amount of local and global wasting energy mechanisms for dissipating the velocity of projectiles have been increased. Furthermore, the interaction between non-rigid projectiles and fiber metal laminate targets as well as permanent deformation of non-rigid projectiles, had important effects on preventing the projectile penetration. By increasing the deformability of projectiles and/or increasing the number of composite plies, permanent deformation of facing plates, fiber breakage, crushing as well as delamination and debonding have been increased and local damage modes in facing plates changed from petalling to plugging. Besides, rigid projectiles possessed less specific perforating energy compared with deformable projectiles and required minimum initial velocity for full penetration.