The Mesh and Height Effects of Rock Sample Failure in Uniaxial Compression by Statistical Damage Method

Abstract

Due to presence of flaws in intact rock such as cracks and voids, rock failure associated with damage evolution becomes significantly discontinuous and difficult to describe. Based on the Weibull function and plastic criterion of Drucker–Prager, a statistical damage method has been implemented by finite element method. Laboratory testing has been conducted to verify in the method and to obtain the mechanical parameters of rock, which show good agreement with the results of the numerical simulation. For studying the size effects of mesh and sample height, appropriate numerical simulations were carried out in the uniaxial compression. The study results show that the failure pattern and strength of rock sample are greatly influenced by the size of mesh and sample height. Smaller the mesh size or more height of rock sample, the lower is the peak and residual is the strength of the rock, moreover failure pattern gradually changes from tensile failure to the shear failure.