摘要
利用单轴压缩条件下砂岩CT资料,对有裂纹出现的σ=20.59～31.03MPa阶段的CT图像利用所设计的裂纹提取滤波器进行裂纹提取操作,其中提取阈值,是在进行敏感性分析后选定的。在所取得的裂纹二值化图像的基础上,利用码尺法、盒计数法、小岛法和Sandbox法对各载荷步下裂纹面积和长度的分维数进行了计算。最后,对裂纹分维数随加载过程的变化进行分析,利用分维数的演化信息讨论砂岩破裂的分形特性。
Firstly,cracks located in the CT images scanned at the stages of stress changing from 20.59 MPa to 31.03 MPa are obtained from the images by means of CT data about sandstone under the uniaxial compression condition. The filter designed in the paper is used to pick up cracks,in which the threshold value is determined after sensitivity analysis. Based on these binary images of crack under each loading step condition,the fractal dimension of area and length of the crack in the sandstone are computed by the methods of yardstick,box-counting,island and sandbox. Finally,the relation between the fractal dimension of crack and the loading process is analyzed,and the fractal feature on the damage and fracture of sandstone is discussed through the evolution information of the fractal dimension.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第S1期2721-2726,共6页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(50649028,50679073)
国家自然科学基金重点项目(90510017)
关键词
岩石力学
砂岩
分形
分维数
裂纹
rock mechanics
sandstone
fractal
fractal dimension
crack
