Numerical methods for characterisation of elevated temperature effects on CFRP interface behaviour using current insertion tests

The non-linear behaviour of the interface and its influence on the propagation of mode II delamination for carbon fibre and epoxy resin laminated composites subjected to thermomechanical loading are highlighted. An innovative mechanical test bench using the Joule heating by inserting electric current has been used. It allows to reveal the role of the interface behaviour at temperatures below the glass transition temperature ( T g ∼ 180°C for the analysed material) and which do not cause mass loss by thermal degradation. The temperature dependence of interface behaviour before the appearance of first signs of damage is shown assuming elastic or viscoelastic ply behaviour. A hybrid approach combinining finite element simulations enriched with experimental data from digital image correlation confirm the apparent non-linear behaviour of the interface as a function of the temperature.