Repair potential of recyclable resins and the impact on fatigue performance

As part of the WiseWind Project, which investigates recyclable resins, this work aims to determine the effect of repair conducted with a heating process on the fatigue properties of biaxial glass fibre reinforced polymer composites. The fatigue performance of two laminates is determined in a strain-controlled fatigue test with a R=0.1 ratio. For a given strain level, the S-N curves obtained are used to assess the potential gain after repairing by heating a specimen subjected to a given number of cycles. This study shows a positive effect of the process on the recovery of stiffness of the pre-damaged specimens, also observed for one specimen from one material with microscopy pictures. Nevertheless, the damage memory seems to play a role in the degradation process during the second loading. In the case of a laminate experiencing a limited drop in stiffness, the number of cycles to reach the failure criteria is extended by almost a factor of three.