研究了混凝土细观脆断模型的网格敏感性,在线弹性断裂力学和应力集中理论的基础上,建立了等效断裂强度准则。利用等效断裂强度准则和最大拉应力准则,在两种不同网格下,对细观模型的单轴拉压破坏过程进行了分析。结果表明,经典的最大拉应力准则具有明显的网格敏感性,而等效断裂强度准则由于将单元大小作为破坏参数,可以较好地克服单元破坏引起的网格敏感性。
The mesh sensitivity in the micro-brittle models of concrete is studied. The equivalent fracture criterion is provided based on linear fracture mechanics and stress concentration theory. Uniaxial tension and compression tests are carried out under two mesh size with equivalent fracture criterion and Rankine criterion respectively, the results show that with Rankine criterion there is distinct mesh sensitivity, on the contrary, the results of equivalent fracture criterion have little mesh sensitivity for having the mesh size as an parameter.