Abstract The meso-deformation evolution in grus is crucial to the mechanical characteristics. Although the macroscopic deformation of grus has been widely studied, its physical meso-scale deformation and shear band evolution have not been well understood. In this paper, high energy X-ray computed tomography (CT) measurements and digital volume correlation (DVC) were performed on a grus sample under triaxial compression in order to quantify shear strain and shear bands in grus. Besides, a series of three-dimensional octahedral shear strain was obtained by DVC analysis. Furthermore, the corresponding evolution of the shear band, content, distribution characteristics and connectivity were investigated. The results show that the shear bands are formed at the stage where the axial strain is equal to 8%; generally, they are obliquely distributed as a whole and connected in an irregular flat strip shape; besides, the failure path may cause the grains to divert or branch due to the anisotropic distribution of grains. Moreover, the octahedral shear strain approximation obeys the χ2 distribution. There are at least two types of distribution of shear bands. Small-scale shear bands may be generated in different areas in the material at the initiation state, whereas the correlation and directionality between the variety of shear bands are slight; while at the shear failure stage and the subsequent stages, a close correlation is found between the shear bands, the direction consistency is significant.

中文翻译：

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动态三维成像和数字体积相关性分析量化格鲁斯的剪切带

摘要 鹤的细观变形演化对其力学特性至关重要。尽管对鹤的宏观变形进行了广泛的研究，但其物理中尺度变形和剪切带演化尚未得到很好的理解。在本文中，高能 X 射线计算机断层扫描 (CT) 测量和数字体积相关 (DVC) 在三轴压缩下的鹤样本上进行，以量化鹤的剪切应变和剪切带。此外，通过DVC分析获得了一系列三维八面体剪切应变。此外，还研究了剪切带、含量、分布特征和连通性的相应演变。结果表明，剪切带形成于轴向应变为8%的阶段；一般来说，整体呈斜向分布，连接成不规则的扁平条状；此外，由于晶粒的各向异性分布，失效路径可能导致晶粒转向或分支。此外，八面体剪应变近似服从 χ2 分布。剪切带的分布至少有两种类型。在起始状态下，材料的不同区域可能会产生小尺度剪切带，而各种剪切带之间的相关性和方向性很小；而在剪切破坏阶段和后续阶段，剪切带之间存在密切的相关性，方向一致性显着。此外，八面体剪应变近似服从 χ2 分布。剪切带的分布至少有两种类型。起始状态下材料的不同区域可能会产生小尺度剪切带，而各种剪切带之间的相关性和方向性很小；而在剪切破坏阶段和后续阶段，剪切带之间存在密切的相关性，方向一致性显着。此外，八面体剪应变近似服从 χ2 分布。剪切带的分布至少有两种类型。起始状态下材料的不同区域可能会产生小尺度剪切带，而各种剪切带之间的相关性和方向性很小；而在剪切破坏阶段和后续阶段，剪切带之间存在密切的相关性，方向一致性显着。