Acoustic emission study and strength analysis of crimped steel-composite joints under traction

Integrated in composite electrical insulators, metal/fibreglass-reinforced-plastic (GRP) joints made of an epoxy rod reinforced with E-glass fibres and of two crimped steel end-fittings are investigated numerically and experimentally. Numerical stress and strain distributions through the bond during the crimping phase and under an axial tensile test are calculated with a solid 3D finite element model and the damage initiation in the composite is highlighted. The simulations are compared to experimental data obtained from several joint specimens tested under pulling on an experimental set-up equipped with strain gauges and an acoustic emission system. Good correlation between the finite element predictions and the test results is found. The numerical and experimental study is also completed with a sensitivity analysis of the main geometrical parameters of the joints.