An experimental system to evaluate impact shear failure of rock discontinuities

Wei Yao, Chonglang Wang, Kaiwen Xia, Xin Zhang

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Conventionally, the evaluation of shear failure of discontinuities in rocks and other geomaterials has been conducted under static shear loading. In such methods, the shear failure behaviors of rock discontinuities are significantly influenced by loading velocities. To evaluate the shear failure process under dynamic loading, in this paper, we propose a new experimental methodology by taking advantages of recently available high-speed optical and mechanical measurement techniques. The methodology utilizes the Hopkinson bar to apply impact loading, and the diagnostics include a dynamic stress wave acquisition system, a digital image correlation (DIC) system, and an acoustic emission (AE) monitoring system. To improve the accuracy of the DIC analysis, an advanced digital speckle pattern and an updated water transfer printing are used to obtain the optimized and consistent speckle pattern. A flexible piezoelectric film sensor is first introduced to acquire AE signals in order to locate AE events accurately. A dynamic impact shear experiment indicates that the normal stress has a significant effect on the peak shear stress of rock discontinuities and the peak shear stress itself is rate dependent. The displacement field along shear directions is quantified using the DIC method, and the initial AE source locations during the impact shear process are determined using the AE monitoring system. We thus conclude that the dynamic impact shear system can systematically characterize the dynamic impact shear process with quantitative details and can further be implemented to study other dynamic impact failure behaviors of rock discontinuities under in situ stresses.

Original languageEnglish
Article number034501
Number of pages11
JournalReview of Scientific Instruments
Volume92
Issue number3
DOIs
Publication statusPublished - 1 Mar 2021
Publication typeA1 Journal article-refereed

Publication forum classification

  • Publication forum level 1

ASJC Scopus subject areas

  • Instrumentation

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