Damage constitutive model of uniaxially compressed coal material considering energy dissipation

Zhang, Peilei; Gong, Fengqiang; Luo, Song; Si, Xuefeng; Xu, Lei

doi:10.1016/j.jmrt.2023.09.281

Cited by 24 publications

(1 citation statement)

References 49 publications

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“…Further, the damage evolution can be characterized by elastic bulk modulus and plastic strain energy release rate [19][20][21]. A large number of laboratory experiments and theoretical analyses have con rmed the intrinsic relationship between strain energy dissipation and release in the process of rock deformation and failure [20,[22][23][24][25]. Based on the above ndings, the stress-strain curve of hysteresis loops obtained by uniaxial compression has been used to characterize the strain energy.…”

Section: Introductionmentioning

confidence: 99%

Rock Crack Initiation Triggered by Energy Digestion

Yan,

Chang,

Manda

et al. 2024

Preprint

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The stress intensity factors with the kinds of critical models are usually obtained from the strength test on laboratory specimens to characterize the rock strength and fracture-ability. However, crack initiation phenomenology for rock material has not been comprehensively understood. In this study, energy theory—an essential character of material property changes—is drawn to evaluate rock crack initiation and study the correlation between rock strength and energy digestion. Uniaxial compression test was conducted on different hardness coefficients rock samples under quasi-static loading conditions and the results of energy evolution, non-linear cumulative digestion, and stored ultimate energy were obtained and compared with a series of results for sandstone. A novel algorithm for the evaluation of rock crack initiation has been proposed and the concept of energy digestion index (EDI) using the ratio of ultimate energy over accumulated energy has been developed to characterize the rock strength. The result shows that crack initiation is related to the maximum growth rate of energy cumulation. Simultaneously, the increasing rate of variable elasticity modulus of rock material gets the peak. The defined EDI has a negative correlation with the rock material's strength and mechanical properties. The relationships between final strength and EDI at crack initiation were also discussed and an assessment of the remaining strength life is introduced using the predicted value by fitting the EDI, leading to a new understanding and exploration for in-situ monitoring of rock damage and failure prediction.

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Section: Introductionmentioning

confidence: 99%

Rock Crack Initiation Triggered by Energy Digestion

Yan,

Chang,

Manda

et al. 2024

Preprint

View full text Add to dashboard Cite

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Uncovering Failure and Cracking Behaviors of Double-Flawed Sandstone Under Compressive-Shear Loading Using Digital Image Correlation (DIC) Technique

Zhou,

Chen,

Wang

et al. 2024

Rock Mech Rock Eng

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The coalescence of flaws provides valuable insights into the failure behaviors of rock masses, which is a critical issue in rock engineering. In this study, a series of compressive-shear tests were conducted on sandstone specimens containing double flaws. The failure and cracking behaviors of specimens with different geometric configurations under various loading conditions were analyzed using the digital image correlation (DIC) technique. The strain and displacement fields effectively demonstrate crack propagation and coalescence, accompanied by the axial load–displacement curve. The results revealed the effect of eccentric and overlapping distance of double flaws on the compressive-shear bearing capacity. The relative displacement method (RDM) was applied to analyze the crack characteristics in this study. Based on the relative displacement behaviors of the cracks, five typical types of crack modes were identified, including tensile mode, shear mode, mixed-I mode, mixed-II mode, and mixed-III mode. Both wing cracks initiated from flaw outer tips and anti-wing cracks generated from flaw inner tips were classified as a tensile mode or mode-I, dominated by normal relative displacement. In contrast, the secondary cracks were categorized as either shear mode or mode-III, which are dominated by tangential relative displacement. The geometry configurations of flaws affected both the coalescent mode and cracking path, which in turn influenced the failure mode of specimens. This study identified and summarized eight types of coalescent modes between double flaws. The findings presented in this paper contribute to a better understanding of the failure behavior of rock masses containing flaws subjected to compressive-shear loads.

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