Experimental Analysis on Deformation Evolution and Crack Propagation of Rock Under Cyclic Indentation
Experimental Analysis on Deformation Evolution and Crack Propagation of Rock Under Cyclic Indentation
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DOI：
10.1007/s00603-012-0309-z
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发表时间：
2013-09
影响因子：
6.2
通讯作者：
Hao Zhang;Haipeng Song;Yilan Kang;Ganyun Huang;C. Qu
中科院分区：
文献类型：
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作者：
Hao Zhang;Haipeng Song;Yilan Kang;Ganyun Huang;C. Qu
压痕引起的开裂可能对岩石钻孔和切割过程产生许多影响。在目前的工作中，对云南砂岩进行了循环压痕试验，以研究变形和破坏过程。通过数字图像相关（DIC）技术获得了样品表面的变形场。研究发现，宏观力-压痕曲线表现出滞后现象，并且在加载-卸载循环过程中残余位移增加。此外，当压痕力达到临界值时，观察到中间裂纹成核，几乎平行于加载轴延伸。这种裂纹总是导致砂岩样品最终失效。实验分析揭示了砂岩在循环压痕过程中的变形破坏机制。通过 DIC 技术，可以轻松计算沿裂纹表面的位移分布，从而计算出裂纹张开位移和断裂韧性等断裂参数。
Indentation-induced cracking may have many implications in rock drilling and cutting processes. In the present work, cyclic indentation tests have been conducted on Yunnan sandstones to investigate the deformation and failure process. Deformation fields on the sample surface have been obtained via the digital image correlation (DIC) technique. It has been found that the macroscopic force–indentation curve exhibits hysteresis and the residual displacements increase during the loading–unloading cycles. Furthermore, a median crack has been observed to nucleate, running almost parallel to the loading axis when the indentation force amounts to a critical value. Such a crack always results in the final failure of the sandstone samples. Experimental analysis reveals the deformation and failure mechanism of sandstone during cyclic indentation. By the DIC technique, the displacement distribution along the crack surface can be easily calculated and, hence, the fracture parameters, such as crack opening displacement and fracture toughness.