考虑T应力的最大周向应变断裂准则研究

岩石的裂纹扩展问题需要确定所采用的断裂准则。为克服最大周向应力准则与材料参数以及平面应力和平面应变无关的不足，该文基于最大周向应变准则思想，推导既包含裂纹尖端r1/2奇异应力项，又考虑非奇异项的应变型断裂准则。通过在KII中考虑摩擦的影响作用，进而实现不同摩擦系数条件下裂纹的起裂角度和起裂强度的研究。运用文中所提出的断裂准则，分别研究含单裂纹的无限板在双轴拉伸和双轴压缩两种条件下的断裂特征，进一步揭示泊松比、侧压系数、摩擦系数等材料参数对裂纹扩展的影响作用，计算结果与相应的试验及理论结果具有较好的一致性。

Study on fracture criterion based on the maximum tangential strain considering the T-stress

One of the most important problems of crack propagation in rock is to use the right fracture criterion under different circumstances. In order to avoid disadvantage of the maximum tangential stress criterion which cannot study the effect of material properties of fracture, we proposed a new strain type of fracture criterion based on the maximum tangential strain criterion. This criterion not only includes the singular stress term (r1/2) at the crack tip but also considers the nonsingular-stress terms. By introducing the friction into KⅡ, the proposed criterion can study the effect of friction on the crack initiation angle and fracture strength. This fracture criterion is used to study the crack initiation in an infinite plate containing a single crack under biaxial tension and compression. The results are well agreed with the experimental and theoretical results. It further reveals the influence of Poisson's ratio, lateral pressure coefficient, friction coefficient on the crack propagation.