No abstract

The resistance of glass-reinforced laminates with different thickness ratio (ratio of glass/epoxy plies thickness to aluminum sheets thickness) subjected to high-velocity impact is investigated experimentally and analytically. The tests are carried out by a light gas gun and a 14 g blunt cylindrical projectile. The ballistic limit velocity and specific perforation energy is used for comparing results. The failure mechanisms that absorbed projectile’s energy during perforation process are studied by examining the damaged samples. This examining helped us to derive an analytical expression to predict the ballistic limit and specific perforation energy. The good agreement between experimental and analytical results shows well mathematical modeling. The results indicate that global deformation of aluminum sheets had the most effect on absorbing energy. Increasing the number of composite plies may enhance the absorbed energy of a fiber metal laminate but also increases weight and cause to be away from the optimum condition. Besides these two procedures, a numerical analysis is done and the results compared with previous ones and are commented upon.

The current study investigated the influence of incorporation of graphene nanoplatelets (GNPs) on quasi-static behavior of composite and fiber metal laminate (FML) panels. The unmodified and modified composite specimens and FML panels with 2/1 configuration were fabricated using a hand lay-up method and investigated through a quasi-static punch and indentation testing. The two sets of tests were conducted with a flat-ended indenter and the loading conditions were the same for all samples, except support spans which were varied. Following experimental testing, possible damages at the punch region were closely investigated and localized and global damages were observed. The results revealed that adding 0.2 wt% GNPs improved the strength and fracture toughness of specimens by delaying the failure modes. On the contrary, GNPs made the bonding between the aluminum and composite interface to weaken.

No abstract

No abstract