Modeling the residual strength and fatigue life of carbon fiber composites under constant amplitude loading

Fatigue life and residual strength prediction of various engineering components and structures are of primary importance because of economy and safety point of view. This article presents the fatigue life and residual strength of Carbon Fiber Reinforced Polymer (CFRP) composites at constant amplitude condition. Experiments were conducted on CFRP composites at different strain rates to determine its ultimate tensile strength. The lowest tensile strength resulting from different strain rates has been used as the ultimate tensile strength for carrying out the fatigue life and residual strength tests. A two-parameter wear out model for predicting the residual strength and the fatigue life of CFRP composites is proposed explicitly by accounting the effect of stress amplitude when the structure undergoes continuous loading. A model was also proposed to predict the fatigue life of CFRP composites based on the endurance limit. The proposed models show good agreement with the experimental results and with the available models in the literature.