An Experimental Study on Impact Resistance of Different Layup Configuration of Fiber Metal Laminates

Fiber metal laminates (FMLs) are composed of thin metal sheets and fiber-reinforced composite layers. Compared to monolithic aluminum alloys, FMLs combine lower density, higher fatigue resistance, and improved damage tolerance. The present study aimed to investigate the low-velocity impact induced by drop-weight instrument and the tensile strength on various lay-up configurations of FMLs fabricated. FML samples were composed of two layers of aluminum 2024-T3 and two layers of epoxy resin, which were reinforced with carbon fabric, glass fabric, and Kevlar fabric made in pairs. In addition, another type of FMLs was developed with carbon/Kevlar fabric under the same circumstances. Force-time histories of impact forces were recorded, and the damaged specimens were inspected using optical microscopy in terms of the impact side, non-impact side, and cross-sectional side. Experimental results indicated that the maximum impact force corresponded to the FMLs that were composed of Kevlar fabric on the impact side and glass fabric on the non-impact side. In addition, the highest tensile strength and Young's modulus among FMLs belonged to FML with Kevlar fabric and glass fabric.