Finite Element Analysis For Surface Cracks In A Finite Elasticity Body

Along with the high-speed development of the modern productions, the new craft, new material and the high strength material have got an extensive application in the structure of aviation, aerospace, pressure vessel components, the nuclear reaction, machine and the civil engineering and so on. When the material adopt with designing for the traditional strength theories under the high speed, the high heat, high pressure and low temperature, there are a lot of fracture accident to happen. The investigation found that the destructive stress less than the ultimate stress of material. So there is a very important realistic signification to investigate the mechanics behavior of fracture for material. At present, only some of simple model or the model with rigid assumptions can be theoretically solved. With the higher cost and the longer period in experimentations, so researchers have to use numerical methods to investigate the fracture behavior, especially to three dimensional surface crack problems;The many numerical results obtained by using finite element method and other methods. But it is found that from the previous investigation results that the effect of the boundaries parallel to the crack on the SIFs is not considered. From the investigations of two-dimensional crack problems reported in Refs, it is found that the effect of the boundaries parallel to the crack on the SIFs is not ignored for comparing crack boundary dimension and crack dimension being less than a certain value. For a center crack problem in rectangular plate in tension, for example, it is found from the numerical results of Ref.This note introduces briefly the actuality about the behavior of fracture mechanics in domestic and overseas. In this note, in order to analyze this behavior numerically, the analytical method for the effect of boundaries parallel to crack on the SIFs is adopted in finite method. Then we analyze the effect of boundaries parallel to crack and crack length on the SIFs. Finally, we analyze the effect of boundaries parallel to crack and crack width on the SIFs. The numerical results show that the effects of boundaries parallel to crack on the SIFs are very obvious. We also compared with Newman's results, from which it is found that the agreement is very good. Especially the last two conditions are prominent for the effect on the SIFs. Meanwhile, in these effects, the SIFs of the free surface are the biggest.