Rock mechanical failure characteristics and energy evolution analysis of coal-rock combination with different dip angles

A coal-rock (CR) combined body can be used to simulate structures of coal and rock strata, and its impact-induced failure characteristic conforms more close to engineering practice. Exploring the mechanical properties and impact energy in a CR combined body contributes to better predictions of rock bursts in coal mines. In the study, the mechanical properties of CR combined bodies with four different inclinations (0°, 15°, 30°, and 45°) of structural planes were measured, and also their failure mechanism was analysed. Based on the theory of particle mechanics, a calculation model for impact energy in a CR combined body with inclinations was established and then verified by using monitored acoustic emission (AE) data. The test results showed that inclination affected mechanical properties and failure characteristics of the CR combined body, i.e., the larger the inclination, the lower the strength and impact energy in the CR combined body and the lower the level of damage. The proposed calculation model for impact energy revealed the mechanical essence of energy accumulation and release of a CR combined body, providing a reference for investigating rock burst in coal mines.

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Dynamic mechanical behaviors of naturally fractured granite subjected to multi-level uniaxial fatigue loads: Insights from fracture and energy evolution analysis

10.22541/au.159325209.90205900 ◽

2020 ◽

Author(s):

yu wang ◽

xuefeng yi ◽

bo zhang ◽

changhong li

Keyword(s):

Energy Evolution ◽

Mechanical Behaviors ◽

Dynamic Mechanical ◽

Evolution Analysis ◽

Naturally Fractured ◽

Multi Level ◽

Fractured Granite ◽

Fatigue Loads

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Experimental Study on Mechanical Properties, Failure Behavior and Energy Evolution of Different Coal-Rock Combined Specimens

Applied Sciences ◽

10.3390/app9204427 ◽

2019 ◽

Vol 9 (20) ◽

pp. 4427 ◽

Cited By ~ 1

Author(s):

Shang Yang ◽

Jun Wang ◽

Jianguo Ning ◽

Pengqi Qiu

Keyword(s):

Kinetic Energy ◽

Failure Modes ◽

Rock Strength ◽

Compressive Loading ◽

Dissipated Energy ◽

Failure Behavior ◽

Peak Strain ◽

Energy Evolution ◽

Coal Rock ◽

Axial Splitting

To investigate the effect of the pure coal/rock strength on the mechanical behavior, failure behavior, and energy evolution of coal-rock combined (CRC) specimens, an AG-X250 Shimadzu Precision Universal Test was used to conduct uniaxial compressive loading, uniaxial cyclic loading, and unloading compression experiments on pure coal, pure rock, and different CRC specimens. The results show that the uniaxial compressive strength, Young’s modulus, and peak strain of the CRC specimen mainly depend on the coal specimen instead of the rock strength. The major failure modes of CRC were the shearing fracture and axial splitting failure, and for the CRC specimen with the same hard rock, the CRC specimen severely failed due to axial splitting cracks. In addition, the released elastic energy Ue, dissipated energy Ud, and kinetic energy Ur increase with increasing rock mass/coal strength, and for CRC specimen with the same coal, the greater the difference in strength between the rock and coal is, the greater the kinetic energy is.

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