Evaluation of interfacial strength for glass fibre cloth reinforced plastics by first fracture detection

This study is concerned with the detection of the initial stages of fracture of plain woven glass fibre cloth reinforced plastics. During the tensile test, the fracture process was recorded on video-tape. These images were analysed using an image analysing system in order to determine the brightness of each image. The initial fracture was identified by the change of brightness of a series of images as a result of debonding at the interface or because of matrix cracking in transverse fibre bundles. The interfacial strength was evaluated by the initial fracture stress. This technique can be applied to the estimation of the interfacial strength of woven fabric composites