Failure Potential Evaluation in Engineering Experiments Using Load/Unload Response Ratio Method

Zhang, Langping; Yu, Huaqing; Yin, Xingyao

doi:10.1007/s00024-011-0370-7

Cited by 13 publications

(4 citation statements)

References 41 publications

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“…Many scholars use different geophysical parameters as responses, and have carried out a large number of experimental studies at different scales, including physical mechanism, experimental studies, numerical simulation and earthquake prediction practice (Yu, 2004;Yu et al, 2006;Yu et al, 2010;Yin et al, 2013;Yin et al, 2002;Zhang H et al, 2005a;Zhang W et al, 2006a;Zhang Y et al, 2006b), and made a series of progress. Experiments and numerical simulations also confirm the correctness of the theory of loading-unloading response ratio (Yin et al, 1995;Zhang et al, 2013). But, in the actual field observation, it is difficult to measure the stress and strain of the block, so it is equally difficult to measure the deformation modulus during loading and unloading (Yin et al, 2017).…”

Section: Introductionmentioning

confidence: 74%

The evolution characteristics of rock fracture instability under cyclic loading on the basis of the enhanced LURR

et al. 2023

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Prospective discrimination of rock instability and fracture is a key problem in mining, slope stability, earthquake triggering, and other research fields. Through the rock fracture experiment, scientists put forward the load unload response ratio (referred to as LURR) to detect the non-linear deformation process of the strain stress curve, judge the degree of rock damage and instability fracture, which is accepted worldwide and has been widely used in seismic risk assessment. But, the extraction of response parameters (including strain, energy, well water level, etc.) are faced with many difficulties in actual observation, which makes the application of results uncertain. In this paper, the change of relative wave velocity is proposed as the loading unloading response parameter. Through rock mechanics experiments, a prospective discrimination method of rock instability and fracture process is constructed. The change characteristics of the LURR in the process of rock instability and fracture under stress are studied, the experiment result show that: when approaching the main fracture, the LURR calculated by taking the transverse strain energy as the response quantity obviously rises and fall back, the acoustic emission energy release rate and event rate are close to exponential acceleration process; The LURR by taking the change of relative wave velocity as the response parameter, first decreases, then fluctuates near zero, and rapidly decreases to below zero when it reaches the critical failure. The change combination of the above parameters’ response ratio can effectively judge the process of rock deformation, instability and fracture under stress. Moreover, this study of the load unload response ratio which takes the change of relative wave velocity as the response parameter, makes up the deficiency of the traditional load unload response ratio method in judging the rock instability of the medium under stress.

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Section: Introductionmentioning

confidence: 74%

The evolution characteristics of rock fracture instability under cyclic loading on the basis of the enhanced LURR

et al. 2023

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“…According to the linear multiaxis fatigue damage model proposed by Yin et al [42], the cumulative damage of coal under cyclic loading at each stress level can be calculated [43]:…”

Section: Geofluidsmentioning

confidence: 99%

Mechanical Behavior Evolution and Damage Characterization of Coal under Different Cyclic Engineering Loading

Wang

2020

Geofluids

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The cyclic loading causes the strength change of porous rocks, which can be frequently encountered in underground coal mining. In order to quantify the cumulative damage of porous coal, multilevel uniaxial cyclic compressive tests were carried out considering different loading frequencies. The results show that under cyclic loading, Young’s modulus of coal shows a first drastic increase and then decrease trend in terms of the number of loading-unloading cycles, while the Poisson’s ratio gradually increased at lower peak stress amplitudes and then increased sharply with peak cyclic stress amplitude until losing load bearing capacity, following a stepwise rising trend. At a higher loading frequency, volumetric compressibility-dilatancy transition is shifted to an earlier time. The loading/unloading response ratio (LURR) was used to evaluate the damage of coal under cyclic loading. It is found that LURR is an effective parameter to evaluate the damage of coaly rock under cyclic loading and is also useful in distinguishing different deformation mechanism at different loading stages. The results also show that the damage of coal can initiate at the early stage of cyclic loading at a low loading frequency; however, the increase in frequency of cyclic loading can delay the damage time, requiring a relatively higher level of peak cyclic stress amplitude.

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“…Based on the assumption that the damage at the fracture limit obeys the Weibull distribution on the mesoscale [ [30][31][32], Zhang et al [33,34] established a relationship between Y and the damage variable D as follows:…”

Section: Relation Between Damage Degree and Number Of Cyclic Impactsmentioning

confidence: 99%

Experimental Study on the Dynamic Mechanical Properties of Large-Diameter Mortar and Concrete Subjected to Cyclic Impact

Sun

Yang

Zhu

et al. 2020

Shock and Vibration

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Rock bursts are typically accompanied by multiple shocks. In order to explore the dynamic characteristics of filling materials in rock burst roadways, we employ the split Hopkinson pressure bar (SHPB) test to analyze the dynamic mechanical response of mortar and concrete under cyclical impact. The SHPB test results of the large-size specimen indicate the improvement in the waveform shape and the reduction in the wave dispersion via the application of the rubber sheet as the pulse shaper. Under cyclic impact, the peak stress and energy utilization ratio of mortar and concrete specimens were reduced, demonstrating obvious fatigue characteristics. The mortar peak stress and energy utilization ratio were observed to be sensitive to the impact times, while those of concrete were sensitive to impact pressure. The damage evolution of mortar and concrete exhibited very similar trends under the cyclic impact load, whereby the impact pressure had minimal effect on the damage evolution.

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Failure Potential Evaluation in Engineering Experiments Using Load/Unload Response Ratio Method

Cited by 13 publications

References 41 publications

The evolution characteristics of rock fracture instability under cyclic loading on the basis of the enhanced LURR

The evolution characteristics of rock fracture instability under cyclic loading on the basis of the enhanced LURR

Mechanical Behavior Evolution and Damage Characterization of Coal under Different Cyclic Engineering Loading

Experimental Study on the Dynamic Mechanical Properties of Large-Diameter Mortar and Concrete Subjected to Cyclic Impact

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