Research of Stress Intensity Factor for Surface Crack in Plane Based on Finite Element

In engineering practice, due to material's fault or some improper operations, a lot of structures and equipments appear semi elliptical surface cracks. As the target of stress concentrate intensity and stress strain field,stress intensity factor is an important basis in determining the safety. A finite plane with semi elliptical surface cracks was chosen. An analytic plane model of finite element with semi elliptical surface cracks was established by the way of1 /4 node method singular element. The model was analyzed to get the solution of stress intensity factors by ANSYS.Taking these elements into consideration,some different models were established and compared. The regularities of distribution on edge line of stress intensity factor were concluded and the affections of elements on stress intensity factor at crack tip were summarized,such as the length of cracks,the depth of cracks and the thickness of plane. In crack tip,stress intensity factors decreased with the length growth of the crack. With the depth growthe of the crack,stress intensity factors increased. Along the edge line,stress intensity factors increased from crack tip to the bottom of the crack.