Experimental study on the spectral characteristics of electromagnetic radiation during creep process of coal
In order to study the response law of electromagnetic radiation spectral changes of coal under uniaxial creep loading conditions,the variation characteristics of electromagnetic radiation spectrum during the entire stage of short-term creep process in the vertical bedding direction of different coal types under uniaxial load were tested,and their variation laws were discussed.The research results indicated that in the process of uniaxial creep step loading,the overall trend of electromagnetic radiation frequency and amplitude of coal body had a similar change law,and the frequency and amplitude of each stage also had their own similar change law.In the whole creep process,the electromagnetic radiation signal frequency of the coal body was in the low frequency stage,mainly concentrated in 0-0.5 MHz,and the electromagnetic radiation frequency band range in the accelerated creep deformation stage was larger than that in the deceleration and constant-velocity creep deformation stages.In the deceleration and constant velocity creep deformation stages,the amplitude changes of electromagnetic radiation frequency were generally in the low amplitude stage.In the accelerated creep deformation stage,due to the exacerbation of coal damage,there were significant fluctuations in the amplitude of electromagnetic radiation frequency.In the late stage of accelerated creep deformation until the sample approaches fracture,the amplitude value of frequency showed a trend of increasing,decreasing,and then increasing.The research results can provide certain experimental and theoretical basis for the accurate perception of damage and failure information during the rheological mutation process of coal and rock,as well as the intelligent monitoring and warning of coal and rock dynamic disasters.
coal rock dynamic disasterstep loading under uniaxial compressionshort-term creepelectromagnetic radiationspectral characteristics