Mechanical Behavior and Fracture Characteristics of Rock with Prefabricated Crack under Different Triaxial Stress Conditions

Li, Zhaolin; Wang, Lianguo; Li, Wenshuai

doi:10.3390/min12060673

Cited by 13 publications

(5 citation statements)

References 42 publications

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“…Li et al [23] found that the intermediate principal stress direction plays a very important role in inducing the direction of rock crack propagation.…”

Section: Overview Of Ultrasonic High-frequency-vibration Rock-breakin...mentioning

confidence: 99%

Research on the Mechanism and Characteristics of Ultrasonically Coupled Mechanical Rock-Breaking Pre-Fracturing Technology

Liu,

Duan,

Huang

et al. 2023

Machines

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In this paper, we propose an ultrasonically coupled mechanical rock-breaking technology, creatively design an ultrasonically coupled mechanical rock-breaking drum, concurrently develop an ultrasonic cracking simulation method based on test coordination, and study the cracking mechanism and characteristics of ultrasonically pre-broken rock in order to increase the rock-breaking efficiency of shearer drums and lengthen pickaxe service life. To further understand the theory behind ultrasonic-coupled mechanical rock breaking, the operation of a fusion drum and the implications of ultrasonic field theory in a solid medium are first examined. Second, the impact and mechanism of the ultrasonic pre-crushing of the target red sandstone are investigated in conjunction with conducting a rock uniaxial compression test and RFPA2D modeling. Furthermore, an ultrasonic pre-crushing fracturing mechanism test of the target red sandstone further reveals the effect and mechanism of ultrasonic fracturing. The efficacy of ultrasonic-coupled mechanical single-cutter cutting is then investigated using the discrete element cutting model (PFC2D) of red sandstone. The results show that under the action of ultrasonic waves with an excitation frequency of 41 kHz, cracks can effectively be produced inside the rock mass of the target red sandstone, and the cumulative amount of acoustic emission is as high as 513, which reduces the strength of the rock mass and disintegrates its internal structure; the average cut-off force of the purely mechanical rock-breaking mode is 6374 N, and that of ultrasonically coupled rock breaking is 4185 N, which is a reduction of 34.34%, and can be attributed to the fact that ultrasonic waves can loosen the structure of the rock mass. This is explained by the ability of ultrasonic vibrations to weaken the structure of rock. The coupled rock-breaking technology not only simplifies mechanical cutting and rock breaking but the lower force can also reduce a pick-shaped trunnion’s wear failure cycle. This improves the environment for subsequent pick-shaped trunnion cutting and rock breaking and prevents the pick-shaped trunnion from being subjected to high-stress loads for an extended period of time so as to prolong its working life.

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“…Li et al [23] found that the intermediate principal stress direction plays a very important role in inducing the direction of rock crack propagation.…”

Section: Overview Of Ultrasonic High-frequency-vibration Rock-breakin...mentioning

confidence: 99%

Research on the Mechanism and Characteristics of Ultrasonically Coupled Mechanical Rock-Breaking Pre-Fracturing Technology

Liu,

Duan,

Huang

et al. 2023

Machines

View full text Add to dashboard Cite

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“…Hence compared to con ning pressure, the internal joints and aws in rock masses have a greater impact on the deformation, strength, and crack propagation form of the rock 7 . Then the stability of rock slopes is mainly controlled by internal joints and aws in the rock mass, and the fracture process of the rock mass can be seen as a macroscopic manifestation of crack initiation and growth [8][9][10][11][12] . The fundamental reason for the rock slope failure under earthquake is the deformation and fracture of the rock mass under external load, which is essentially the process of crack initiation and growth under seismic load.…”

Section: Introductionmentioning

confidence: 99%

A hybrid finite-discrete element method for modelling cracking processes in sandy mudstone containing a single edge-flaw under cyclic dynamic loading

Zhang,

Xu,

Zhang

et al. 2024

Preprint

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Rock mass deformation and failure are macroscopic manifestations of crack initiation, propagation, and coalescence. However, simulating the transition of rocks from continuous to discontinuous media under dynamic loads remains challenging. This study proposes a hybrid finite-discrete element method (HFDEM) to model crack propagation. Uniaxial compression tests on sandy mudstone with a single edge-flaw are simulated using HFDEM, and the results are compared with laboratory tests. The effects of pre-existing flaw inclination angle and dynamic loading frequency on the crack process are investigated. Results show that under dynamic loading, rock samples exhibit significantly higher compressive strength compared to quasi-static loading, which increases with dynamic frequency. Crack initiation angle also increases with flaw inclination angle and dynamic frequency. Experimental and numerical simulation results demonstrate crack initiation at the defect's tip, formation of wing cracks, and a combination of tensile and shear failure modes. The comparative analysis shows that HFDEM successfully captures crack interaction mechanisms and accurately simulates the overall failure behavior of cracked specimens. This study provides valuable insights into crack development and failure of rocks under seismic loads, offering guidance for engineering practices.

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“…Hence compared to confining pressure, the internal joints and flaws in rock masses have a greater impact on the deformation, strength, and crack propagation form of the rock 7 . Then the stability of rock slopes is mainly controlled by internal joints and flaws in the rock mass, and the fracture process of the rock mass can be seen as a macroscopic manifestation of crack initiation and growth 8 – 12 . The fundamental reason for the rock slope failure under earthquake is the deformation and fracture of the rock mass under external load, which is essentially the process of crack initiation and growth under seismic load.…”

Section: Introductionmentioning

confidence: 99%

A hybrid finite-discrete element method for modelling cracking processes in sandy mudstone containing a single edge-flaw under cyclic dynamic loading

Zhang,

Xu,

Zhang

et al. 2024

Sci Rep

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Rock mass deformation and failure are macroscopic manifestations of crack initiation, propagation, and coalescence. However, simulating the transition of rocks from continuous to discontinuous media under cyclic dynamic loading remains challenging. This study proposes a hybrid finite-discrete element method (HFDEM) to model crack propagation, incorporating a frequency-dependent cohesive-zone model. The mechanical properties of standard sandy mudstone under quasi-static and cyclic dynamic loading were simulated using HFDEM, and the method's reliability was verified through experimental comparison. The comparative analysis demonstrates that HFDEM successfully captures crack interaction mechanisms and accurately simulates the overall failure behavior of specimens. Additionally, the effects of pre-existing flaw inclination angle and dynamic loading frequency on rock failure mechanisms were investigated. The numerical results reveal that rock samples exhibit significantly higher compressive strength under dynamic loading compared to quasi-static loading, with compressive strength increasing with higher cyclic dynamic load frequencies. Furthermore, by analyzing the strength characteristics, crack propagation, and failure modes of the samples, insights into the failure mechanisms of rocks under different frequency loads were obtained. This study provides valuable insights into crack development and failure of rocks under seismic loads, offering guidance for engineering practices.

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Mechanical Behavior and Fracture Characteristics of Rock with Prefabricated Crack under Different Triaxial Stress Conditions

Cited by 13 publications

References 42 publications

Research on the Mechanism and Characteristics of Ultrasonically Coupled Mechanical Rock-Breaking Pre-Fracturing Technology

Research on the Mechanism and Characteristics of Ultrasonically Coupled Mechanical Rock-Breaking Pre-Fracturing Technology

A hybrid finite-discrete element method for modelling cracking processes in sandy mudstone containing a single edge-flaw under cyclic dynamic loading

A hybrid finite-discrete element method for modelling cracking processes in sandy mudstone containing a single edge-flaw under cyclic dynamic loading

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