Assessment of stress intensity factor and aspect ratio variability of surface cracks in bending plates

Abstract

In this paper, a closed-form solution for the stress intensity factor ( K) of semielliptical surface cracks in plates subjected to pure bending, obtained by Newman and Raju using 3D finite elements, is critically evaluated. This solution is compared to a recommended solution by the Society of Experimental Stress Analysis (SESA). It is also compared to photoelastic K measurements. In addition, in this study the aspect-ratio variability of surface cracks under fatigue loading is predicted and compared with experimental data and also with the predictions of other empirical equations proposed by Porten, Kawahara and Kurihara, and lida. Finally, the usefulness of this equation for the prediction of fatigue life of surface cracks is evaluated by a comparison with experimental results.