拉应力准则

针对二维裂纹的破坏演化特征，建立了外荷载逐次增量及在最大拉应力准则下，沿裂纹扩展方向的单元自动追加的裂纹扩展动态过程的DDM跟踪方法。

According to the characteristics of damage progress of two-dimensional crack , the DDM tracking of dynamic process of crack propagation has been developed for external load increment and automatic unit addition along the direction of crack propagation under the criteria of maximum tensile stress .

提出了基于弹性损伤力学的本构关系，以最大拉应力准则和摩尔库仑准则作为损伤发生的阈值，并借助复合材料破坏过程分析（MFPA）程序进行受力分析。

The constitutive equation based on elastic damage mechanics is put forward , using the max tensile-strain criterion and Mohr-Coulomb criterion as the damage threshold . At the same time , a stress analysis is carried out , using the Material Failure Process Analysis ( MFPA2D ) .

混凝土细观结构的破坏由最大拉应力准则判别，对于软化段，采用了应力-张开位移模型以缓解计算结果的网格依赖性。

The tensile strength failure criterion is used , and stress-displacement model is adopted to alleviate the sensitivity on mesh size in the softening region .

用线弹性断裂力学对连续介质中三维裂纹（K（Ⅲ）≠0）破裂的拉应力断裂准则提出了补充性假说和相应的计算方法（第一主微分面定点法）。

The normal stress criterion of three-dimensional brittle fracture ( Km ≠ 0 ) of continuum medium is further studied by using the theory of linear elastic fracture mechanics . Some complementary assumptions and the corresponding calculation method ( method of locating principal differential planes ) are proposed .

修正的拉应力裂纹扩展准则及裂隙水压对裂纹扩展的影响

The modified tensile stress crack propagation criterion and influence of cranny hydraulic pressure on crack propagation

本文采用最大拉应力单元开裂准则，改进了非线性分析的迭代流程，使其最大可能地模拟实际结构的开裂情况，进而可以基于分布裂缝模式计算裂缝发生位置、裂缝间距、裂缝开展深度和宽度。

The criterion of the element with the maximum tensile stress will crack is presented , the iteration flow diagram of nonlinear analysis is improved , and then the position , gap and width of crack can be computed based on ′ smeared ′ crack model .