Abstract:

The stress intensity factors are obtained for a semi-infinite plate with a edge crack or an internal crack or a semi-infinite crack under concentrated forces at two points by the use of an alternating method. The method is based on two problems of the plane elastic theory. The first problem is an infinite plate with a centrical crack, which the faces are loaded with arbitrary distribution stress. The second problem. is the boundary of the half plate subjected to the arbitrary load. The solutions of these problems are obtained by a integral. For the first problem the solution is obtained by integrating the solution of an infinite plate with four symmetrically located normal forces on the crack faces. For the second problem, the solution is obtained by integrating the solution of a half plate with two symmetrically located normal forces on the boundary. Then the bounday conditions are satisfied alternatively. The integrals are evaluated by using Gruss rule with 32 nodes, and five iterations are used generally. The numerical iteration results are one percent more accurate. For some cases the results arc shown in curves.

Key words: stress intensity factor, semi-infinite plate, alternating method