Stress intensity factors in the specimen with a surface semi-elliptical defect

Abstract

In this work, equations for stress intensity factors calculating in the specimen with a surface semi-elliptical defect in order to interpret experimental data of the surface crack growth rate tests at elevated temperatures were obtained. In the commercial finite element code ANSYS 3D finite element models with surface flaws for the range of the relative crack depth b/t = 0.1…0.7 and the aspect ratio b/a = 0.3…1 were generated. For these ratios stress intensity factors were calculated based on the finite element method. For the same configurations of semi-elliptical crack fronts using Murakami's stress intensity factors handbook stress intensity factors were calculated. It has been established that the results of numerical calculations and the Murakami's handbook have a similar pattern of the stress intensity factors distribution. For the stress intensity factors calculating in the specimen with a surface semi-elliptical crack to the Murakami's handbook specimen geometry-dependent stress intensity factor functions a correction function was added. The results allow to interpret the experimental data of the surface crack growth rate tests of the specimen at elevated temperatures.