An improved KI expression for a semi-elliptical surface crack in a finite plate subjected to uniform tension

Abstract

Newman-Raju solution for a surface cracked plate under uniform tension has been widely used in surface crack-related problems. However, comparisons of Newman-Raju solution with numerical stress intensity factor (KI) solutions indicated the accuracy of Newman-Raju solution at the depth point inferior to that at the surface point. Therefore, we feel there is a need to improve the accuracy of Newman-Raju solution. With the domain integral method provided by Abaqus, numerical KI solutions with high accuracy were obtained for a wide range of surface crack configurations. By fitting assumed functions to the numerical results, a KI expression was developed for a surface cracked finite plate subjected to uniform tension. The proposed expression can be used to determine KI at an arbitrary point on the crack front. A detailed analysis was conducted on the accuracy of the KI expression, with two application ranges respectively allowing for accuracy better than 3% and 5% provided. The KI expression yields better accuracy than Newman-Raju solution within the application ranges that cover most surface crack configurations occurring in practice, and the accuracy of Newman-Raju solution at the crack depth point has been substantially improved.