考虑刚度劣化影响的岩石峰后应变软化模型

为反映刚度劣化对峰后力学行为的影响,提出描述刚度劣化程度的新参数,即刚度劣化指数.将峰后黏聚力和峰后内摩擦角假设成塑性剪切应变的函数,基于广义莫尔库仑准则,建立岩石峰后应变软化模型.利用北山花岗岩试验数据对模型进行验证.结果表明:模拟结果与试验数据规律吻合度较高,建立的峰后应变软化模型较为合理,为岩石峰后软化过程的模拟提供新的方法.

Post-Peak Strain Softening Model of Rock Considering Stiffness Degradation Effect

In order to reflect the effect of stiffness degradation on the post-peak mechanical behavior, a new parameter describing the degree of stiffness degradation, the stiffness degradation index was proposed. Assuming that the post-peak cohesion and the post-peak internal friction angle are functions of the plastic shear strain, the post-peak strain softening model of rock is established based on generalized Mohr-Coulomb criterion. Beishan granite test data is used to verify the model. The results show that the simulation result are in good agreement with the experimental data, indicating the reasonableness of the established post-peak strain softening model, a new method for the simulation of post-peak softening of rocks is presented.