两相材料界面裂纹的起裂方向及断裂参量研究  

Study on directions of crack orientation and failure characteristics of bi-material interface crack

作　　者：师俊平[1] 曹小杉[1] 胡义锋[1] 罗峰[1] 

机构地区：[1]西安理工大学工程力学系,西安710048

出　　处：《应用力学学报》2014年第3期418-422,493,共5页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(10972180)

摘　　要：采用FRANC2D软件研究了两相材料含界面裂纹的断裂特性。通过在材料界面利用CASCA手动生成界面裂纹并在裂纹尖端附近设置1/4奇异等参元,得到了界面裂纹的复应力强度因子;数值模拟得到了界面裂纹的起裂方向,并分析了界面裂纹的破坏特征。计算结果表明:1/4奇异等参元很好地描述了裂纹尖端场的1/r(1/2)奇异性,FRANC2D软件能够模拟界面裂纹的扩展方向,可以得到界面裂纹尖端的应力场和复应力强度因子,为界面裂纹的断裂特性的进一步分析提供依据。The calculation of crack propagation can be implemented using special grid mobile by the software FRANC2D. Because no simplification needs to be made to the geometrical model during the procedure of the grid division, and the grid can be automatically remeshed with the propagation of cracks, the software FRANC2D can be used to analyze and simulate the propagation of cracks with arbitrary shape in the plane structure under any boundary conditions and initial conditions. In this article, the fracture behavior of the bi-material with interface crack is investigated using FRANC2D. The complex stress intensity factor of interface crack is obtained through manually generating interface crack in the boundary of the bi-material and placing the 1/4 singular isoparametric elements near the crack tip, the directions of crack orientation are determined by numerical simulation, and the failure characteristics of the interface crack are analyzed numerically. The results indicate that, the 1/4 singular isoparametric elements can describe the 1 / r singularity of the interface crack tip accurately, the directions of interface crack propagation can be simulated by the software FRANC2D, and the complex stress intensity factor and the stress field near the interface crack tip can be obtained, which provide reference for further analysis of the fracture behavior of interface cracks. The prediction for the direction of crack propagation and the complex stress intensity factor in the software FRANC2D is helpful to further investigation of interfacial fracture and provides guidelines for engineering fracture analysis.

关 键 词：界面裂纹 应力强度因子 起裂方向 扩展路径 奇异等参元 

分 类 号：O346.1[理学—固体力学]