三维双材料结构的应力奇异性分析

Stress singularity analyses in three-dimensional bi-material structure

应用有限单元法子模型技术,对具有不同界面角的三维双材料结构的应力奇异性进行了分析。结果表明,应用子模型技术估算三维双材料结构的应力奇异性指数是有效的。然后分析了界面端线和界面端点处附近奇异性指数,得到了一些重要而有趣的结果。最后对消除三维双材料结构应力奇异性的几何条件进行了讨论。

The singular stress analyses for three-dimensional bi-material structure with various edge angles are performed using FEM (finite element method) sub-modeling technique. It is shown that FEM sub-modeling technique is valid for estimating the index of stress singularity for three-dimensional bi-material structure. The index of singularity along the stress singularity line and at the vertex are analyzed, and some important and interesting results are obtained. Furthermore, the disappearance conditions of stress singularity along the intersection of interface with the free surface are investigated. The results indicate that the singularity index at the vertex shows some 'singular' characteristics and cannot be estimated using two-dimensional theory. The conditions eliminating stress singularity in a three-dimensional joint are the same as those in the two-dimensional theory for plane strain state.