Uniaxial Compressive Behaviour of Carbon Fibre-Epoxy Laminates – Part 2: Notched

Abstract

Compressive failure behavior of composite laminates containing open hole was investigated systematically through the mechanical tests and damage monitoring studies of the multidirectional composite laminates (T300/924C [45/-45/0/90]_3s and T800/924C [45/0/-45/90]_3s ). Fibre microbuckling in the 0( plies, surrounded by delamination, occurred in the vicinity of the hole prior to catastrophic fracture. The microbuckling, which leads to extensive in and out-of-plane fibre kinking, extends stably under increasing load before becoming unstable at a critical length of 2-3mm (depends on the specimen geometry) along the specimen width. The effect of a single 3mm diameter hole in a 30mm wide plate is to reduce the gross section strengths by about 40% and 38%, respectively when compared to the unnotched failure strength. The failure strengths were predicted successfully the open hole strength for both materials, less than 7% difference when compared to the measured experimental results.