Failure energy and strength of Al/CFRP hybrid laminates under flexural load

Fibre metal laminates (FMLs) are a class of hybrid laminates made of composite material plies and metal sheets; they are used for applications where extraordinary mechanical properties are needed, due to their high damage tolerance, low weight, and high strength. In the present work the behaviour of different types of aluminium-carbon fibres FMLs was studied; in particular, hybrid laminates were produced varying the layer thickness and the bonding conditions, and then they were tested according to the three-point bending procedure to evaluate the relevant flexural strength and the fracture energy. These mechanical properties were influenced by both the bonding conditions and the layer thickness; in fact, the presence of the adhesive at the composite/metal interface made the flexural strength decrease and the fracture energy increase, while the presence of a unique aluminium sheet caused the increment of the flexural strength and a slight decrease of the fracture energy.