Possible Mechanism of Infrared Radiation Reception: The Role of the Temperature Factor

et al. 2023

Sustainability

Coal mining often causes periodic disruption in the rock mass around the stope. The study of the deformation and failure characteristics of cyclic loading and unloading sandstone is very critical for gaining a thorough understanding of the mechanisms of rock damage, degradation, and failure. This kind of investigation is very helpful in determining the precursors of rock failure and the instability of engineering structures. In this research study, the properties of acoustic emission and infrared radiation of cyclic loading and unloading sandstone are explored using a cyclic loading and unloading sandstone experiment. Based on acoustic emission and infrared radiation, the loading–unloading response ratio of rock is established. It is found that the response variables of sandstone during the loading stage based on acoustic emission (AE) counts and the loading–unloading response ratio based on average infrared radiation temperature (AIRT) both rise suddenly in the last cycle, which may be a precursor of “acoustic-thermal” approaching rock failure. On this basis, the quantitative analysis index of infrared radiation of differential infrared energy change rate (DIECR) is proposed, that is, the change of square of ΔAIRT in unit time, and based on AE counts and DIECR, the loading–unloading response ratio of “acoustic-thermal” is defined. It is found that the “acoustic-thermal” loading–unloading response ratio suddenly increases during the penultimate cycle of loading and unloading. This feature can be taken as the initial precursor of rock failure. Together with the “acoustic-thermal” imminent failure precursor of rock, it constitutes the “initial precursor-imminent failure precursor” combined with the internal fracture and surface infrared radiation temperature field during the cyclic loading and unloading process of rock, realizing the hierarchical monitoring and early warning of cyclic loading and unloading rock failure. The research results lay a theoretical and practical foundation for using infrared radiation to monitor engineering disasters caused by rock fracture and failure in mining engineering.

Section: Introductionmentioning

confidence: 99%

Precursors of Cyclic Loading and Unloading Sandstone Failure Based on “Acoustic-Thermal” Loading–Unloading Response Ratio

et al. 2023

Sustainability

“…The thermal information can be effectively evaluated using infrared radiation (IR) to monitor the rock failure. Various researchers have noted that IR characteristics changed significantly during rock deformation, sliding friction, crack development, and dilatation under loading [24][25][26][27][28][29]. These changes in IR characteristics can be reflected using different indexes, i.e., Average Infrared Radiation Temperature (AIRT) and Infrared Radiation Variance (IRV) during the induced fracturing process [27,[29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Prediction of Sandstone Dilatancy Point in Different Water Contents Using Infrared Radiation Characteristic: Experimental and Machine Learning Approaches

Khan

et al. 2022

Lithosphere

In rock mechanics, the dilatancy point is always occurring before rock failure during loading process. Water content plays a significant role in the rock physiomechanical properties, which also impact the rock dilatancy point under loading process. This dilatancy point significantly plays a warning role in the rock engineering structures stability. Therefore, it is essential to predict the rock dilatancy point under different water contents to get an early warning for effective monitoring of engineering projects. This study investigates the water contents effects on sandstone dilatancy point under loading in the presence of infrared radiation (IR). Furthermore, this IR was used for the first time as an input parameter for different artificial intelligence (AI) techniques to predict the dilatancy point in the stress-strain curve. The experimental findings show that the stress range in stress-strain curve stages (crack closure and unstable crack propagation) increases with water content. However, this range for deformation and stable crack propagation stages decreases with water content. The dilatancy stress, crack initiation stress, and elastic modulus are negatively linearly correlated, while peak stress and stress level are negatively quadraticaly correlated with a high (R2). The absolute strain energy rate, which gives a sudden increase at the point of dilatancy, is used as the dilatancy point index. The stress level is 0.86 σmax at the dilatancy point for dry rock and decreases with water content. This index is predicted from IR data using three computing techniques: artificial neural network (ANN), random forest regression (RFR), and k-nearest neighbor (KNN). The performance of all techniques was evaluated using R2 and root-means-square error (RMSE). The results of the predicted models show satisfactory performances for all, but KNN is remarkable. The research findings will be helpful and provide guidelines about underground engineering project stability evaluation in water environments.

“…The infrared radiation (IR) will change during rock loading. [5][6][7][8][9][10][11] Monitoring the IR of rocks can determine the deformation and failure characteristics of rocks and may provide reliable information for predicting the precursor of rock failure. [12][13][14][15] However, the change in characteristics of IR during the process of cyclic loading and unloading rocks is still unknown.…”

Section: Introductionmentioning

confidence: 99%

Cyclic fatigue characteristics of rock failure using infrared radiation as precursor to violent failure: Experimental insights from loading and unloading response

Fatigue Fract Eng Mat Struct

et al. 2020

In this research paper, a new method is developed that can be used as a precursor of violent rock failure. It is based on measuring the characteristics of rock failure using infrared radiation (IR) under uniaxial cyclic loading and unloading. The loading–unloading response ratio (LURR) is determined based on IR indexes such as average infrared radiation temperature (AIRT) and infrared radiation temperature rate (IRTR). The results show that the LURR based on AIRT revealed an overall rising trend and mutation that occurred in the last cycle, which can be used as a precursor of the imminent rock failure. By contrast, the LURR based on IRTR has a noticeable ‘mutation‐rapid decrease’ in the middle and later periods of cyclic loading and unloading, which can also be considered as an early precursor of rock failure. Combined with the precursors of the imminent rock failure, the categorized warning of rock failure is recognized.