The investigation of the effecfs of fatigue on the residual strength of composite materials

Abstract

This paper presents the results of an investigation into the effects of fatigue on the residual strength of a 0°/90° CFRP composite. Cycling was carried out at five different stress levels over a range of 60 % to 90 % of the ultimate tensile strength of the composite. For a given stress level a relationship has been derived between the residual strength and the fatigue life of the composite. This relationship the fatigue characteristics for any given stress level without the need for time consuming and expensive testing. It has been shown that stress concentrations affect a crossplied laminate to a lesser extent than unidirectional laminates and homogeneous materials.