Prediction of fatigue crack propagation in center cracked steel plate strengthened with prestressed CFRP strip

Evaluating the fatigue behavior of steel structures strengthened with prestressed carbon fiber reinforced polymer (CFRP) is of great significance for structural repair and rehabilitation. In this paper, an analytical model based on linear elastic fracture mechanics considering the additional elongation of the steel plate caused by the central crack opening was proposed to predict the fatigue behavior of prestressed CFRP strips strengthened steel plates. The finite element model calibrated by experiments was used to verify the proposed model. The results showed that the proposed model can predict the stress state of various components, the stress intensity factor SIF amplitude, the fatigue crack growth life, and the minimum prestress of CFRP strips required for crack arrest under different strengthening conditions with high accuracy. This study will be conducive to a better application of the prestressed CFRP strengthening of thin-walled steel structures under fatigue loading.