Microscopic damage evolution of anisotropic rocks under indirect tensile conditions: Insights from acoustic emission and digital image correlation techniques

作     者：Chaoqun Chu Shunchuan Wu Chaojun Zhang Yongle Zhang Chaoqun Chu;Shunchuan Wu;Chaojun Zhang;Yongle Zhang

作者机构：School of Civil and Resource EngineeringUniversity of Science and Technology BeijingBeijing 100083China Department of Civil&Mineral EngineeringUniversity of TorontoToronto ON M5S 1A4Canada Faculty of Land Resources EngineeringKunming University of Science and TechnologyKunmiing 650093China China Railway Sixth Group Limited CompanyBeijing 100036China 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2023年第30卷第9期

页      面：1680-1691页

核心收录：

学科分类：081901[工学-采矿工程] 0819[工学-矿业工程] 08[工学] 081203[工学-计算机应用技术] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：financially supported by the National Natural Science Foundation of China (No.51934003) the Major Science and Technology Special Project of Yunnan Province,China(Nos.202102AF080001 and 202102AG050024)。 

主　　题：anisotropic rock failure mechanism acoustic emission digital image correlation Brazilian test 

摘      要：The anisotropy induced by rock bedding structures is usually manifested in the mechanical behaviors and failure modes of rocks.Brazilian tests are conducted for seven groups of shale specimens featuring different bedding angles. Acoustic emission (AE) and digital image correlation (DIC) technologies are used to monitor the in-situ failure of the specimens. Furthermore, the crack morphology of damaged samples is observed through scanning electron microscopy (SEM). Results reveal the structural dependence on the tensile mechanical behavior of shales. The shale disk exhibits compression in the early stage of the experiment with varying locations and durations. The location of the compression area moves downward and gradually disappears when the bedding angle increases. The macroscopic failure is well characterized by AE event location results, and the dominant frequency distribution is related to the bedding angle. The b-value is found to be stress-dependent.The crack turning angle between layers and the number of cracks crossing the bedding both increase with the bedding angle, indicating competition between crack propagations. SEM results revealed that the failure modes of the samples can be classified into three types:tensile failure along beddings with shear failure of the matrix, ladder shear failure along beddings with tensile failure of the matrix, and shear failure along multiple beddings with tensile failure of the matrix.