Tensile strength and its scatter of unidirectional carbon fibre reinforced composites

Zero (along the fibre direction) and 90 degree (transverse to the fibre direction) tension tests of Carbon Fibre Reinforced Plastics (CFRP) using a great number of specimens were conducted. Tensile properties and their scatter were evaluated by means of the data base. Materials used in this study were seven kinds of carbon fibres and three kinds of epoxy resins. Reinforcing fibre and matrix resin properties strongly affected on 0 and 90 degree properties of CFRP respectively. In 0 degree tension tests, fracture mode of specimen varied in each material, and a relationship between the scatter of strength and the fracture mode existed. From the results of 90 degree tension tests, some differences of interfacial properties between each laminate were also detected. According to some considerations on fracture mechanism in 0 degree tension test, it was deduced that the fracture mode depended on the balance of fibre, matrix and interface properties.