Meso-numerical simulation of rock triaxial compression based on the damage model

Abstract

The mathematical model of brittle rock triaxial compression simulation is established and solved by the secondary development of COMSOL, and the numerical model is verified by rock uniaxial compression experiment and triaxial compression experiment. The meso-damage evolution of brittle rock under triaxial compression is simulated, and the influence of heterogeneity coefficient, confining pressure and loading rate on stress-strain curve and ultimate failure mode are studied. The results show that: The enhancement of rock heterogeneity makes the core failure position more dispersed, and when the coefficient of heterogeneity decreases from 10 to 0.8, the young’s modulus decreases by 14.92%, and the peak strength decreases by 35.45%; The increase of confining pressure makes the failure events gather to the fault surface, and when the confining pressure increases from 0MPa to 40MPa, the young’s modulus increases by 22.57%, the peak strength increased by 94.47%, and the residual strength increased by 112 times; The increase of loading rate makes the rock failure unit relatively dispersed, resulting in two fault planes, and when the loading rate increases from 0.01 × 10−3 to 0.2 × 10−3, the peak strength increases by 7%. This paper provides a reference for more accurate, rapid and comprehensive study of rock triaxial compression numerical simulation.