An Experimental Study on the Impact Resistance of Carbon-Kevlar-Fibers- Reinforced Aluminum and Carbon-Glass-Fibers-Reinforced Aluminum Laminates

Fiber metal laminates (FMLs) a combination of thin metal sheet and fiber reinforced composite layers. Compared to monolithic aluminum alloys, these materials combine lower density, higher fatigue resistance and improved damage tolerance. In this research, low velocity impact induced by drop-weight instrument on different lay-up configuration was studied experimentally. The lay-up configuration for FMLs consist of laminates: Aluminum 2024-T3 and carbon fibers- Kevlar fibers reinforced with epoxy resin (carbon fiber on top: FML-CK and Kevlar fiber on top: FML-KC) and Aluminum 2024-T3 and carbon fibers-glass fibers reinforced with epoxy resin (carbon fiber on top: FML-CG and glass fiber on top: FML-GC). The force-time histories of impact forces were recorded. The damaged specimens were inspected using optical image for impact side, non-impact side and cross-sectional image. Experimental results exhibited that maximum impact force for FML-CK about 840 N is higher than FML-KC but there was some delamination in FML-CK. The post impact optical images showed that there was bigger damage area zone around the FML-KC in front of specimen and back face of specimen. It also determined maximum impact force for FMLCG about 1200 N is higher than FML-GC. The post impact optical images showed the damaged area for FML-GC is more than FML-CG in back face of specimen but damage area in front of specimen was similar for both FMLs.