Abstract: Based on the strain softening theory, the authors present a simulation of the development from localized ductile zone to crenulation cleavage in specimen which can be used to verify the theory of MEMC. With the FLAC^3D, the rock specimen with the shape parameters and the stress of loading rate ruled by corresponding standard regulations were designed. The numerical simulation of the forming process of the localized shear belts under the uniaxial compression shows that the conjugate angle of the shear belt is 107.7° after strain softening, verifying the MEMC and explaining the random behavior expression of the contour map of shear strain on the cross section.

Key words: maximum effective moment criterion (MEMC), localization of shear strain, FLAC3D, strain softening theory, convergence of differential scheme

摘要： 基于应变软化理论, 模拟岩石加载应力时出现局部化韧性剪切带到发育褶劈理的过程, 从而验证最大有效力矩准则的有效性。根据相关试验规程和标准规定的试样形状、尺寸和应力加载速率, 采用FLAC^3D软件, 对岩石试样在单轴轴对称压缩条件下局部化剪切带的形成过程进行数值模拟, 应变软化后得到的共轭剪切应变集中带共轭夹角为107.7°, 论证了最大有效力矩准则的109°规律, 同时也合理解释了横切面的剪切应变等值线的随机性表现。

关键词: 剪应变局部化集中带, FLAC3D, 应变软化, 差分格式收敛, 最大有效力矩准则