Variation of Out-of-Plane Constraint and Its Effects on Fracture  

作　　者：Fei Xu Yulong Li Wanlin Guo 

机构地区：[1]Department of Mechanical Engineering, Tokyo University of Science, Noda,2788510, Japan [2]School of Aeronautics, Northwestern Polytechnical University, Xi''an,710072, P. R. China School of Aeronautics, Northwestern Polytechnical University, Xi''an,710072, P. R. China School of Aeronautics and Astronauts, Nanjing University of Aeronautics and Astronauts,Naniing,210016, P.R.China

出　　处：《上海交通大学学报》2004年第z2期212-216,共5页Journal of Shanghai Jiaotong University

摘　　要：The limitations of using one-parameter to describe the crack-tip fields have prompted investigators to consider better descriptions of the crack tip fields. The two-parameter descriptions, such as J-Q theory, have been an important development in this field. But under the consideration of plane strain and three-dimensional problem, the effects of the out-of-plane stress can not be neglected In this paper, effects of the in-plane constraint as well as the out-of-plane constraint are studied by aid of the finite element method on the plane strain condition. It is obvious that both the in-plane constraint (Q factor) and the out-of-plane constraint (Tz = σzz/(σxx + σyy) ) affect the crack tip fields.Several important features of the out-of-plane constraint are described out based on the simulation results. At the end of this paper, a three-parameter formulation is proposed, in which both the in-plane constraint and the out-of-plane constraint are considered. Comparing with the results of the FEM numerical simulation, the three-parameter description can provide a better prediction near the crack tip.

关 键 词：IN-PLANE CONSTRAINT OUT-OF-PLANE CONSTRAINT three-parameter FORMULATION crack TIP field ELASTIC-PLASTIC 

分 类 号：N55[自然科学总论]