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为考察岩石材料细观结构特征对于裂纹扩展机制的影响,首先借助偏光显微镜和SEM观测了3类岩石材料中材料内部组织结构,分析了各自非均质程度和晶粒大小关系。之后,对3类岩石的带I型初始裂纹的3点弯曲试样进行了落重冲击试验,同时采用高速摄影获得了不同裂纹速度下的裂纹扩展形态。将这些结果对照分析,研究了3类岩石中裂纹扩展过程与各自材料组织结构的非均质程度和晶粒大小的关系,得出初步结论:组织结构内部特征尺度越大,动态裂纹所能达到的终极速度就相对越小。反之亦然。
In order to investigate the effect of the mesostructural features of rock materials on the crack propagation mechanism, the internal structure of the materials in three types of rock materials was observed by means of polarization microscope and SEM. The relationship between the heterogeneity and grain size was analyzed. After that, the drop impact test was carried out on the 3-point bending specimens with type I initial crack of three types of rocks, and the crack growth modes under different crack speeds were obtained by high-speed photography. Based on these results, the relationship between the crack growth process and the heterogeneity and grain size of the structure of the three kinds of rocks was studied. The preliminary conclusions are drawn: the larger the internal scale of the structure, the dynamic crack can reach The ultimate speed is relatively smaller. vice versa.