Damage And Fracture In Notched Woven Fabric Composites Under Cyclic Loading

摘要

Fatigue of notched woven GFRP and CFRP laminates under tension-tension fatigue loading wasinvestigated. It was shown that the damage morphology which developed under cyclic loading of afour-layer quasi-isotropic glass laminate, based on eight harness satin weave (8HS) reinforcement, wassimilar to that observed previously under quasi-static loading. Under fatigue loading, however, theextent (length) of the damage zone prior to final fracture was greater than seen under quasi-staticloading and the extent increased with reducing fatigue stress in the fatigue cycle. This trend wasmodelled reasonably well by the fracture mechanics element of a model developed to predict thestrength under quasi-static loading. CFRP laminates – which were also four-layer quasi-isotropic layups,but based on plain weave (PW) or five harness satin (5HS) reinforcement – showed a slightimprovement in residual strength with increasing fatigue cycles. The improvement was not sufficientlyhigh, however, to suggest that the effect of the notch had been eliminated completely.