Stress and damage analysis of composite–aluminium joints used in electrical insulators subject to traction and bending

Numerical and experimental stress and failure studies are performed on metal/fibreglass-reinforced-plastic (GRP) joints used in composite electrical insulators consisting of an epoxy tube reinforced with E-glass fibres and of two aluminium fittings fastened to the tube with an adhesive. Subjected to traction and bending, the joints are modelled with axisymmetric 2D and solid 3D finite elements respectively. Numerical stress and strain distributions through the bond are calculated and the damage initiation in the composite is highlighted. The simulations are compared to experimental data obtained from several joint specimens tested on an experimental set-up equipped with strain gauges and an acoustic emission system. Good correlation between the numerical predictions and the experimental results is found.