Experimental and FE study of hybrid laminates aluminium carbon-fibre joints with different lay-up configurations

The use of composite materials in industry is growing due to various technological advances in composite materials accompanied by improvements in the structural adhesives used to bond them. Fibre metal laminates (FML's) are hybrid composite structures based on thin sheets of metal alloys and plies of fibre-reinforced polymeric materials. The fibre/metal composite technology combines the advantages of metallic materials and fibre-reinforced matrix systems. The aim of the present study is to use a concept similar to that used in FML to increase the peel strength of composite materials and increase the joint strength of hybrid laminates aluminium carbon-fibre adhesive joints. Carbon fibre-reinforced plastic (CFRP) composites were modified by including one or several aluminium sheets during the laminate manufacture to enhance the composite through the thickness properties. The objective was to identify the joint configuration that gives the best joint strength improvement in relation to the CFRP only reference joint. An adhesive developed for the aeronautical industry was used to manufacture single lap joints for tensile testing. Experimental and numerical studies were undertaken on modified CFRP joints to investigate the joint strength of different lay-up solutions to prevent delamination of adherends.