Characteristics of Fatigue Failures in Fibre-Reinforced Plastics

摘要

Macro- and micro-fractography studies were made of static and fatigue failures in unfilled epoxy resins and glass and carbon fiber reinforced epoxy resin composites. Fatigue striations were observed in the resins, similar to those in metals and in the static specimens, parabolic cusps, Wallner lines and other features were observed. Delaminated surfaces of the glass reinforced plastics showed fatigue striations of a different morphology to that in the unfilled resin. This is believed to be the first time such striations were observed in fiber composites with a fiber content of 70% by volume. The directions of the striations are closely analysed and from them conclusions are drawn about local stress distributions and local crack propagation in fiber composites.