Equivalent surface defect model for fatigue life prediction of steel reinforcing bars with pitting corrosion

Pitting corrosion is one of the most common corrosion damages for steel reinforcing bars. Fatigue crack usually initiates and propagates from pitting corrosion due to stress concentration and cross-section reduction. In this study, a novel equivalent surface defect model is proposed to quantitatively describe the corrosion effect for fatigue life prediction using both maximum corrosion degree and the aspect ratio. Due to the stochastic nature of the fatigue crack growth, both single crack and multiple crack cases are discussed. The proposed equivalent surface defect model is used for corrosion fatigue life prediction which includes the crack initiation life and the crack propagation life. The overall method is validated using fatigue testing data.