Prediction of fatigue life for CFRP-strengthened steel plates

Carbon fibre reinforced polymer (CFRP) composites have proven to be effective in enhancing the load-carrying capacity and in extending the fatigue life of structural steel elements. Most studies have relied extensively on experimental testing and numerical simulations. It is important to develop some efficient analytical methods for predicting the fatigue behaviour of the composites repaired structures. In this paper, a simple analytical method is presented for estimating the fatigue crack growth and fatigue life of the CFRP repaired steel plates. Two types of fibre sheets are studied. These are normal modulus (E=240 GPa) and high modulus CFRP (E=640 GPa) sheets. Both double-sided and single-sided repairs are investigated. The analytical models are verified by experimental results.