基于无网格法的含缺陷岩石变形局部化数值模拟研究

利用自主开发的基于无网格法的岩石力学计算分析程序，采用Mohr-Coulomb破坏准则，考虑材料塑性屈服后的软化特性，研究单轴压缩条件下含一个缺陷的岩石试样的变形特性，探讨含缺陷材料的岩石变形局部化的演化规律。计算结果表明，岩石试件的破坏是一个渐进破坏的过程；加载过程中试件中的缺陷弱粒子首先出现粒子破坏并产生声发射，随加载进行试件产生微裂隙并扩张形成一个变形局部化带，局部化带扩张、发展，最终形成一个明显的剪切破坏带，缺陷粒子对试件的破坏起到了控制作用。岩石的声发射记录了岩石材料的塑性破坏过程，岩石试件的剪切破坏带与塑性区的发展具有非常类似的规律，但塑性区面积要大于剪切破坏带，从所处位置来看剪切破坏带位于塑性区之内，通过研究声发射特征信息发现变形局部化发生在应力-加载步（应变）达到峰值强度前。

Numerical simulation of deformation localization for defective rock based on meshless method

Based on the meshless method, the self-developed program is proposed to analyze the rock mechanics. In the present program, the Mohr-Coulomb criterion is adopted and the softening of material after plastic yield can be considered. The deformation of defective rock under uniaxial compression can be analyzed; and the evolution of deformation localization in defective rock can also be clarified. The calculation results show that the process of destruction of rock specimen is evolutionary. The material destruction and acoustic emission occurs at the defective weak particle of rock specimen with the loading process. A localized deformation zone produced with the crack expanding. A distinct shear failure zone formed in the rock specimen with the expansion and development of localized deformation zone. Defective particles played a control role in the specimen damage process. Rock acoustic emission records the plastic failure process of rock materials. The development of shear failure zone and plastic zone of rock specimen has a very similar way. However, the plastic area is greater than the shear failure zone; and the shear failure zone is located in the plastic zone. It can be concluded that the localized deformation occurs before the stress-loading step (strain) reaches the point of peak strength.