大理岩受压破坏的数字图像界面元法模拟

SIMULATION OF MARBLE FAILURE IN COMPRESSION WITH DIGITAL IMAGE INTERFACE STRESS ELEMENT METHOD

从岩体内部细观组成出发,以结构控制论为指导,研究其受压的破坏机制。以锦屏水电站大理岩为例,利用Matlab软件数字图像处理工具编制图像处理程序,对大理岩试样的照片进行分析,得到大理岩试样的灰度图像,像素灰度值可以描述试样表面的细观非均匀性,同时利用几何转换和网格生成技术将像素单元转化为力学计算需要的网格单元;基于室内单轴压缩试验,得到大理岩试样破坏现象,获得数值模拟所需的力学参数,结合像素单元灰度信息对材料单元材料属性赋值,得到细观非均质结构模型;然后利用不连续介质力学的界面应力元法对大理岩单轴受压破坏过程进行数值模拟,得到考虑非均质性引起的局部应力和变形,根据局部的应力和变形可以解释由于内部细观结构非均匀性产生的宏观破坏现象。

Based on the inside meso-constitution of rock and guided by the structure control theory,failure mechanism of rock in compression is studied.Photographs of marble from Jinping hydropower is processed with the digital image processing techniques.Images of marble can be transformed into grayscale images and the gray value of pixel matrix can describe the mesoscale constitution and inhomogeneity of marble.Using geometry algorithms and mesh generation techniques,elements of pixels can be transformed into meshes for numerical simulation.Failure phenomenon of uniaxial compression and required material parameter are got from indoor test.With gray value distribution mesostructure is evaluated parameters.Numerical simulation of mesostructure of marble is carried out with interface stress element method for discontinuity medium.Local stress and deformation can be got as a result of inhomogeneity.The result can interpret the macro phenomena of test because of inhomogeneity.