NEW EMPIRICAL STRESS-INTENSITY-FACTOR EQUATIONS FOR SURFACE CRACKS

This paper presents the new empirical formulas of stress-intensity-factor (SIF) for surface cracks due to tension and pure bending loads. A SIF distribution function is chosen based on the numerical results obtained by simulating the fatigue crack growth and the SIF and shape for a surface crack of given dimensions is obtained using the method. Such empirical formulas of SIF for surface cracks are obtained by curve fitting to the numerical results. Predictions of SIF for surface cracks in plates of finite width and thickness are made using the empirical formulas, and comparisons with the known solutions of semi-ellipse surface cracks are presented. The results obtained in this paper are considered to be an alternative to the evaluation of SIFs for surface cracks.