不同围压作用下岩石损伤破坏的数值模拟

Numerical simulation of damage and failure of rocks under different confining pressures

利用RFPA2D对岩石在不同围压下损伤破坏演化过程进行了数值模拟 ,基于岩石损伤定义分形维数以描述试样在各种加载条件下微破裂的演化过程。计算结果表明 :分形维数和损伤变量随着荷载的增加逐渐增大 ,岩石的起始损伤随着围压增加而被延迟 ,试样强度随着围压的增加而增加 ,其宏观破坏符合Mohr -Coulomb破坏准则。

A numerical analysis has been conducted to evaluate the damage evolution and the fracture process of brittle rock under different confining pressures by using RFPA 2D . A fractal dimension D  associated with material damage is defined to describe the damage process of the specimen subjected to tensile or compressive load.It is found that the fractal dimension D  and the damage variable ω increase progressively with loading. The initial damage is delayed by the increase of confining pressure. The results show that the specimen is strengthened by the confinement and fails according to Mohr-Coulomb failure criterion.