DISTRIBUTIONS OF SIFS FOR SYMMETRICAL PART-ELLIPTIC AND SEMIELLIPTIC SURFACE CRACKS ITS PLATES SUBJECTED TO CRACK FACE SHEAR LOADING

The distributions of SLFs K-II, K-III and their ratios along crack fro nts of symmetrical part-elliptical (PE) surface cracks with a critical inclination angle beta(c) in plates subjected to uniform crack face s hear loading were evaluated using three-dimensional FEM. The results a re then compared with the corresponding results obtained for semi-elli ptical (SE) surface cracks. The differences between PE and SE cracks i n distributions of K-II, K-III are small at positions where phi/phi(c) less than or equal to 0.625, but are appreciable at positions where p hi/phi(c) >0.625. The distribution of the K-II/K-III ratio is mainly d ependent on the crack aspect ratio a/c and the crack front inclination angle beta. The ratios K-II/K-III at the corner points of the PE crac ks with beta = 66.8 degrees and nu = 0.3 vary from 2.06 to 2.21 for ge ometries in this study. However for SE cracks they vary from 19 to 35. The PE cracks are very different from the SE cracks. (C) 1997 Elsevie r Science Ltd.