Dynamic strain field for granite specimen under SHPB impact tests based on stress wave propagation

Jiong Wang; Lei Ma; Fei Zhao; Bangguo Lv; Weili Gong; Manchao He; Peng Liu

Underground Space (Oct 2022)

Dynamic strain field for granite specimen under SHPB impact tests based on stress wave propagation

Jiong Wang,
Lei Ma,
Fei Zhao,
Bangguo Lv,
Weili Gong,
Manchao He,
Peng Liu

Affiliations

Jiong Wang: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
Lei Ma: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
Fei Zhao: College of Geosciences and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, China; Corresponding author.
Bangguo Lv: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
Weili Gong: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
Manchao He: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
Peng Liu: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China; School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China

Journal volume & issue: Vol. 7, no. 5
pp. 767 – 785

Abstract

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The full-field strain of rock material under dynamic compression load was studied using the high-speed three dimensional digital image correlation (3D-DIC) method. The dynamic test was conducted on Laizhou granite using a split Hopkinson pressure bar (SHPB) method. Wave propagation, dispersion and radial inertial effect on the specimen were found by DIC results. A recovery of strain in the post-peak stage was detected on the specimen by DIC, which was unrevealed in the traditional one-dimensional theory method. It can be found that the strain measured by strain gauge was a calculated average one, whereas the strain measured by 3D-DIC could reflect more variation details. Specifically, the testing principle with impact loads and rock dynamic behavior was re-examined using stress wave propagation theory. The theoretical results showed that the specimen reached equilibrium after a series of wave reflections and transmissions and its stress was infinitely close to the initial value of 109.2 MPa. Moreover, the specimen had the calculated maximum strain of 0.52% and strain rate of 15.11 s−1, improving the reasonable agreement with the experimental results and requirements of rock mechanical properties measured by SHPB technology.

Published in Underground Space

ISSN: 2096-2754 (Print); 2467-9674 (Online)
Publisher: KeAi Communications Co., Ltd.
Country of publisher: China
LCC subjects: Technology: Engineering (General). Civil engineering (General): Engineering geology. Rock mechanics. Soil mechanics. Underground construction
Website: https://www.keaipublishing.com/en/journals/underground-space/

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