基于数字图像处理的含孔洞裂纹花岗岩破裂过程数值模拟

摘要

在细观尺度上，采用数字图像处理技术表征花岗岩中由石英、长石和云母等材料的形状、大小及分布对花岗岩材料造成的非均匀性，结合RFPA －DIP程序建立了能准确反映材料真实细观结构的含缺陷花岗岩数值模型，并进行了常规单轴压缩模拟试验，再现了外载荷作用下含缺陷花岗岩的真实破裂过程。试验结果表明：花岗岩的预制孔洞裂纹对其最终破坏产生了重要影响；在单轴压缩试验中，由于花岗岩中各矿物颗粒不同的力学特性影响，试件中出现应力集中现象并萌生局部裂纹，且细观结构直接决定着裂纹的扩展路径，各局部裂纹的贯通导致试件最终产生拉伸破坏。%At meso-scale level ,the digital image processing technologies are applied to charactrerize the heterogeneity for the distribution ,the shape and size of fifferent minerals in granite ,according to RFPA -DIP code ,a numerical model of granite containing flaws is thus developed ,and also the regular simulating laboratory test of uniaxial compression is conducted to visually observe the real fuilure processes of granite .The results show that precrack of granite has a great effect on its ulti-mate filure;in the test of uniaxial compression ,due to the impact of different mechanical properties of granite minerals ,the stress concentration phenonemnon occures in a specimen and local crack also appears ,the expansion path of crack directly relies on the microstructure and the specimen tensile damage is eventually resulted from the cutthrough of every local crack .