基于CT图像单轴受载煤样损伤计算

Coal damage calculation under uniaxial loading based on CT images

针对CT图像的特点,分别从像素与体素两种尺度定义了表面孔隙率与体孔隙率.利用数字地形模型方法计算表面孔隙率,给出了基于工业CT灰度图像体孔隙率的计算方法.对煤样单轴加载下不同阶段的CT图像进行分析,获得了煤样表面孔隙率与体孔隙率随应力变化关系曲线.两种孔隙率都能较好地反映煤样内部损伤变化,表面孔隙率反映的是像素级的孔隙,体孔隙率反映了像素内部的孔隙,更能体现CT图像的特点.

According to the characteristics of CT images, the surface porosity and voxel porosity are defined in pixel and voxel scales respectively. The Digital Terrain Model （DTM） method is applied to calculate the surface porosity, and the method for calculating voxel porosity is also developed based on industrial CT grey images. In a case study, using the proposed methods, the CT coal images under different uniaxial loadings are analyzed, and the relation curves between two types of porosities and its stress are separately obtained. All of these porosities sufficiently reflect the inner damage in coal samples. The surface porosity shows the surface pore in pixel scale while the voxel porosity reflects the inner pore in pixel scale. The voxel porosity describes well the characteristics of CT coal images.