三维介质中复合型裂纹扩展的断裂准则

断裂准则是评定含裂纹构件或结构的工作状态是否安全的基准和依据。本文从三维介质中复合型裂纹问题的分析入手,考虑裂纹尖端小范围屈服区对裂纹扩展的影响,提出了描述三维介质中任意形状裂纹扩展规律的F₀准则和E₀准则。这两个准则均与现有的实验资料吻合得很好,而且还有一个较为突出的特点,即能反映Ⅰ—Ⅱ—Ⅲ型复合裂纹和Ⅱ—Ⅲ型复合型裂纹中KⅢ对裂纹开裂角的贡献。这一特点是S准则^1]、MG准则^9]、C判据^10]和W判据^11]等一些断裂准则不具有的。

FRACTURE CRITERION OF THE MIXED MODE CRACK PROPAGATION IN THE THREE-DIMENSIONAL MEDIUM

Fracture criterion is the fundation and norm of judging whether the working state is steady. Consequently, beginning with the analysis of mixed mode crack problems in the three-dimensional medium, and having considered the effect of little plastic yield zone near a crack tip on breaking, this paper suggests two new dual-parameter fracture criterions(Fe criterion and Ee criterion), They are rather identical with the experimental data.