Reinforcement of CFRP joints with fibre metal laminates and additional adhesive layers

Abstract

The use of fibre metal laminates (FMLs) offers significant improvements over more traditional materials applied in aircraft structures, such as metallic alloys. The use of this type of materials offers weight reduction, improved damage tolerance characteristics and enhanced safety due to a synergetic combination of the advantageous properties of both composites and metallic alloys.The main objective of this work was to study the effect of reinforcing a basic carbon fibre reinforced polymer (CFRP) joint with titanium laminates and/or with additional adhesive layers in the interfaces between titanium and composite, following different lay-up configurations. The lay-up configuration that led to the best results in terms of failure mode and failure load, was found to be the configuration using titanium laminates on a basic CFRP substrate and additional layers of film adhesive in between the metal laminate and the CFRP. A numerical model using finite element analysis with cohesive zone elements was also developed, with the aim of studying the performance of the different proposed configurations, correlate the models with the experimental results, and to aid the identification of the optimal material to use for reinforcement of the CFRP adherend.