岩石细观结构对其变形强度影响的数值分析

利用数字图像处理技术表征岩石的非均匀性,并映射到有限元网格中,建立了能比较准确地反映岩石细观结构的数值模型。通过对花岗岩数字图像的处理,利用该模型进行花岗岩单轴压缩数值试验,研究花岗岩细观结构对其变形和强度的影响。研究表明,花岗岩细观结构对应力集中影响显著,在不同方向对花岗岩进行加载时,其抗压强度差异较大,表现出较强的各向异性行为,但对花岗岩弹性模量的影响很小。基于数字图像的数值分析方法为研究岩石细观力学性质提供了一种新的方法。

Numerical analysis of influence of rock mesostructure on its deformation and strength

Digital image processing method is used as a tool to represent the heterogeneity of rock, which can be introduced into the finite element method; and a numerical model considering the real mesostructure of rock is established. By using this method to represent the heterogeneity of granite, a numerical specimen of granite is built to carry out uniaxial compressive tests. The influence of granite’s mesostructure on its deformation and strength is studied. The results show that the mesostructure of granite has an important effect on stress concentration under loading. The compressive strength of granite is evidently different when loading under different directions, and presents anisotropic behavior. But the influence of mesostructure of granite on its elastic modulus is very small. The digital image-based numerical method proposed provides an effective tool to study the mesomechanical behaviors of rock and rock-like materials.