The effect of STF-Kevlar composite materials on the impact response of fibre metal laminates

Many studies have confirmed that composite laminates made of metal and fiber reinforced composites have an excellent performance, especially when subjected to impact and fatigue loading, while maintaining a low weightto-strength ratio. This paper presents an investigation on the impact resistance of shear thickening fluid (STF)Kevlar composites-based fibre metal laminates (FMLs) subject to low velocity projectile impact. Firstly, the different surface treatments of aluminium alloy were carried out to identify the best bonding strength between the aluminium and composite layers, with the effect of 30V-20min anodizing treatment being identified as the best one. Secondly, impact tests were conducted on pure Kevlar fabric and STF-Kevlar composite fabric to compare their load bearing capacity and energy absorption, showing the latter with more than doubled energy absorption. Subsequently, FMLs based on STF-Kevlar and pure Kevlar fabrics were subjected to low velocity projectile impact. It is found that the impact resistance of the STF-FMLs made with one layer of STF-Kevlar composite fabric is almost equivalent to that of the FMLs made with two layers of pure Kevlar fabric. STFKevlar fabric, as a reinforcing material, has a significant contribution to the enhancement of the energy absorption of STF-FMLs.