Deformation Failure Characteristics and Loading Rate Effect of Sandstone Under Uniaxial Cyclic Loading and Unloading

Zhu, Xiaoxi; Li, Yangyang; Wang, Changxiang; Sun, Xin; Liu, Zhanxin

doi:10.1007/s10706-018-0674-9

Cited by 27 publications

(5 citation statements)

References 17 publications

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“…The axial strain of coal samples can be obtained by Equation (5). Therefore, the calculation equation of the volume strain of coal samples is obtained as follows [34]:…”

Section: Uniaxial Compressive Strength Of Coal Samples At Different Imentioning

confidence: 99%

Mechanical Properties and Damage in Lignite under Combined Cyclic Compression and Shear Loading

Bai

Chen

et al. 2020

Sustainability

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In this paper, uniaxial cyclic compression and shear test was carried out for lignite samples. The effects of inclination angle (θ) and upper limit of cyclic stress (σmax) on mechanical properties of coal samples were analyzed, and the damage variables of coal samples were studied based on energy dissipation theory. The results show that the uniaxial compressive strength (UCS) of coal samples after uniaxial cyclic compression and shear tests decreases with the increase of the upper limit of cyclic stress and inclination angle. The shear stress component generated by the increase of inclination angle can effectively reduce the UCS and increase the damage degree of coal samples. With the increase of inclination angle, the failure mode of coal samples is changed from tensile failure (θ = 0°), the combined tensile failure and shear failure (θ = 5°) to shear failure (θ = 10°). The peak axial and radial strain of coal samples first increases rapidly and then stagnates. The peak volume strain rapid increases and then stagnates (θ = 0° and θ = 5°). When the inclination angle is 10°, the peak volume strain first decreases rapidly and then stagnates. Even if the upper limit of cyclic stress is lower than its UCS, it will still promote the propagation of micro cracks and the generation of new cracks and increase the internal damage of coal samples. With the increase of the cycle number, damage variables of coal samples after uniaxial cyclic compression and shear tests nonlinearly increase, and the growth rate decreases gradually.

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“…The axial strain of coal samples can be obtained by Equation (5). Therefore, the calculation equation of the volume strain of coal samples is obtained as follows [34]:…”

Section: Uniaxial Compressive Strength Of Coal Samples At Different Imentioning

confidence: 99%

Mechanical Properties and Damage in Lignite under Combined Cyclic Compression and Shear Loading

Bai

Chen

et al. 2020

Sustainability

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“…There are some differences in the strength and deformation characteristics between cyclic loading and monotonic loading for rock. Generally, the strength of rock under cyclic loading is marginally smaller than that under monotonic loading [5], and the stress-strain relation under cyclic compression exhibits a peculiar massing effect and ratcheting effect. There are two explanations for the massing effect or hysteresis: elastic energy dissipation resulting from friction or stick-slip between the inner fissures [6]; and hysteresis due to the phase difference between the stress and strain [7], which could be suitable for rock subjected to cyclic loading with a relatively high frequency.…”

Section: Introductionmentioning

confidence: 99%

Hysteresis Behavior Modeling of Hard Rock Based on the Mechanism and Relevant Characteristics

et al. 2022

Sustainability

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The modeling of cyclic behavior in rock remains a challenge due to complex deformation characteristics. This paper studied the mechanical behaviors of granite samples under uniaxial cyclic loading and unloading through cyclic compression tests and acoustic emission (AE) monitoring. Then, a comprehensive body that consisted of an elastic element, plastic element, and friction element was proposed to describe the stress–strain relationship with respect to cyclic behavior, in which the friction element was connected in parallel with the serial combination of the elastic element and plastic element. Finally, the parameters of the proposed model were calibrated based on the mechanism analysis and backpropagation (BP) neural network. Results show that the behavior during unloading is primarily elastic and is accompanied by the obstruction of friction. During reloading, the behavior changes from elastic to elastic–plastic before and after the Kaiser point. The tangential modulus of the elastic element is dynamic in a linear positive correlation with elastic strain and a linear negative correlation with plastic strain; specifically, the elastic strain controls the variation process of the elastic modulus while the plastic strain determines the lower limit. The constitutive law of the plastic element is expressed by a logistic function, which means that the plastic strain increases in a trend of acceleration–deceleration. The friction element plays a major role in processing the massing effect, and the plastic element is prompted before the historical maximum stress, which reflects the ratcheting effect and Felicity effect. The reliability of the proposed constitutive model is confirmed by the comparison of the simulated stress–strain curves with the experimental curves.

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“…Moreover, different water immersion times have been demonstrated to greatly affect the physical and mechanical parameters of crushed rock (Baud et al, 2000;Chen et al, 2018;Xiong et al, 2011;Li et al, 2018;. Crushed coal and rock subjected to cyclic loading and unloading tests have exhibited obvious cyclic hysteresis loops (Badge & Petros, 2005;Fan et al, 2016;Deng et al, 2017;Liu et al, 2011Liu et al, , 2016Zhu et al, 2019). The energy dissipation characteristics were also analyzed by calculating the strain energy density.…”

Section: Introductionmentioning

confidence: 99%

Archives of Mining Sciences

Sun,

Zhang,

Yan

et al. 2020

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COMPRESSIVE DEFORMATION CHARACTERISTICS OF CRUSHED SANDSTONE BASED ON MULTIPLE EXPERIMENTAL FACTORSIn this study, the compressive deformation of crushed sandstone was tested using a crushed rock deformation-seepage test system, and the effects of various factors, including crushed rock grade, grade combination, water saturation status, and stress loading method (i.e., continuous loading or cyclic loading and unloading), on the compressive deformation of crushed sandstone was analyzed from four perspectives including stress-strain, bulking coefficient, deformation mechanism and energy dissipation. The results indicate that the stress-strain relations of crushed sandstone are closely associated with all factors considered, and are well represented by exponential functions. The strain observed for a given applied stress increased with increasing crushed rock grade throughout the loading period. Crushed sandstone grades were combined according to a grading index (n), where the proportion of large-grade rocks in the sample increased with increasing n. The bearing capacity of a water-saturated crushed sandstone sample with n = 0.2 was less than that of an equivalent dry sample for a given applied stress. The stress-strain curve of a water-saturated crushed sandstone sample with n = 0.2 under cyclic loading and unloading was similar to that obtained under continuous loading. Observation and discovery, the deformation mechanism of crushed sandstone was mainly divided into four stages, including crushing, rupture, corner detachment and corner wear. And 20% of the work done by testing machine is used for friction between the crushed sandstone with the inner wall of the test chamber, and 80% is used for the closing of the void between the crushed sandstone, friction sliding, crushing damage.

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Deformation Failure Characteristics and Loading Rate Effect of Sandstone Under Uniaxial Cyclic Loading and Unloading

Cited by 27 publications

References 17 publications

Mechanical Properties and Damage in Lignite under Combined Cyclic Compression and Shear Loading

Mechanical Properties and Damage in Lignite under Combined Cyclic Compression and Shear Loading

Hysteresis Behavior Modeling of Hard Rock Based on the Mechanism and Relevant Characteristics

Archives of Mining Sciences

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