T应力对岩石材料裂纹尖端起裂特性的影响

发布时间：2019-02-24 17:19

【摘要】：传统最大周向应力理论只考虑奇异应力项,而忽略非奇异应力项,这导致脆性材料在分析裂纹尖端起裂特性时,理论分析的结果与实验结果不能完全吻合。基于此,本文通过综合考虑Williams展开式中奇异应力项和非奇异应力项(T应力),建立了修正的裂纹尖端起裂准则,重新分析了裂纹尖端的起裂特性。研究结果表明:(1)当裂纹发生纯I型断裂,T应力超过临界点时,裂纹起裂角发生偏转,裂纹更容易起裂;(2)当裂纹发生纯II型断裂时,随着T应力的增加,裂纹起裂角增大,裂纹更容易起裂;(3)Williams展开式中非奇异应力项对于裂纹起裂特性有重要的影响,本文理论比传统理论计算的起裂角与实验结果更加吻合。
[Abstract]:The traditional maximum circumferential stress theory only considers the singular stress term but neglects the nonsingular stress term which leads to the theoretical analysis of crack tip initiation characteristics of brittle materials and the experimental results are not completely consistent. Based on this, a modified crack initiation criterion is established by considering the singular stress term and the nonsingular stress term (T stress) in the Williams expansion, and the crack initiation characteristics of the crack tip are reanalyzed. The results show that: (1) when the crack occurs pure mode I fracture and T stress exceeds the critical point, the crack initiation angle deflects and the crack starts more easily; (2) when pure II mode fracture occurs, the crack initiation angle increases with the increase of T stress, and the crack initiation is easier; (3) the non-singular stress term of the Williams expansion has an important effect on the crack initiation characteristics, and the theory in this paper is more consistent with the experimental results than that calculated by the traditional theory.
【作者单位】：中建三局集团有限公司;
【分类号】：TU45

【相似文献】