Effects of Shear Damage on the Torsional Behaviour of Carbon Fibre Reinforced Plastics

Abstract
The torsional modulus and damping capacity of uniaxial specimens of carbon fibre reinforced epoxy resin have been measured as a function of strain amplitude, proportion and type of fibre and of fibre surface treat ment. The specimens were then twisted to shear failure and the measure ments repeated. The values of shear strength observed were analysed in the light of the modulus and damping capacity values. The significance of such measurements in the mechanical testing of these materials has been demonstrated.