A Research On The Fatigue Life Prediction Of Fibre-Reinforced Plastics Laminates

Fiber Reinforced Plastic(FRP) has been widely used in aircraft, spacecraft, watercraft and transportation because of its excellent mechanical characteristics. Fatigue strength is one of the important mechanical properties for engineering materials. The fatigue behavior of FRP has been investigated by many researchers in the world in the past decades. Many models to predict fatigue life and to describe the other characteristics of FRP have been presented, but there are still many problems left to be further investigated for the engineering application. The widely used models to explain fatigue characteristic of FRP are reviewed firstly in this thesis, and then a fatigue cumulative rule based on strength degradation damage model was presented, in which the parameters affecting fatigue strength, such as ultimate strengths of fiber and laminates, fibre orientations, loading, are included. The presented model can predict fatigue life and residual strength of composite laminates under constant and varied amplitude loading. It was been verified that the presented model rationally explains the damage development law of FRP by cited experimentation date. A S-N curve model to describe the connection between load and fatigue life of FRP was set up in the present paper based on the fatigue mechanism of FRP. Several sets of experimentation date were employed to verify the proposed S-N curve model, and the results show that comparing to the other commonly used S-N curve model, the presented S-N curve model is superior to other models in the regression of experimental data. Moreover, the presented S-N curve model needs fewer material constants and they are obtained more easily.