Damage Detection and Damage Mechanisms Analyses in CFRP Laminate Bolted Joints

Abstract

This paper discusses bearing damage in CFRP laminates around loaded holes under static and fatigue loads. It studies damage initiation and propagation by the ‘deply method’, ‘X-ray radiographs’ and ‘scanning electron microscope method’. The testing program also was performed to study the effect of temperature and moisture on bolted static bearing strength and it s fatigue life. This paper shows delaminations, fiber fractures, splits and interfacial debondings, etc., in CFRP internal laminates. The damage features were recorded by charts and photographs. The test results showed that fiber bundle fracture initiated on the internal laminates and progressed toward the exterior laminates with increasing load. The results also showed bearing areas around loaded holes were related to the fiber orientations of each laminate. The damage specimens were detected and analysed to study damage mechanism.