煤受载破坏声电信号波形持续时间特征研究

    Study on waveform duration characteristics of acoustic and electrical signals of coal damage under load

    • 摘要: 为探究煤样受载破坏时声电信号持续时长规律,对不同加载速率下煤样单轴加载破坏过程声电信号进行了全波形同步采集,对比分析了煤样破坏过程声电信号时序特征及完全破坏阶段的声发射与电磁辐射的波形特征与持续时长。结果表明:煤样单轴加载破坏过程,声电信号响应有较好的协同性,加载速率越大,主破坏时产生的声电信号更为密集且强度更高;声电信号随加载具有阶段性变化特征,压密与弹性阶段无明显声电信号,加速破坏阶段声电信号逐渐丰富且幅值升高,完全破坏阶段声电信号幅值在主破坏发生时达到最大,并在峰后同步衰减;不同加载速率下煤样主破裂时声电信号持续时长在毫秒级,声发射持续时长明显大于电磁辐射,约为其2-3倍,随加载速率增大,二者持续时长均明显增加,且倍数随加载速率增加而增大。

       

      Abstract: In order to explore the rule of the duration of the acoustic electric signal when the coal sample is damaged by loading, the full waveform synchronous acquisition of the acoustic electric signal during the uniaxial loading failure process of the coal sample under different loading rates is carried out, the time sequence characteristics of the acoustic electric signal during the coal sample failure process are compared and analyzed, and the waveform characteristics and duration of the acoustic emission and electromagnetic radiation in the complete failure stage are emphatically analyzed. The results show that: in the process of uniaxial loading failure of coal samples, the response of acoustic and electrical signals has a good synergy, the higher the loading rate is, the denser and stronger the acoustic and electrical signals are generated during the main failure; the results show that the AE signal changes with the loading stage, and there is no obvious AE signal in the compaction and elastic stage; in the accelerated failure stage, the AE signal is gradually enriched and the amplitude increases; in the complete failure stage, the amplitude of the AE signal reaches the maximum when the main failure occurs, and decays synchronously after the peak; under different loading rates, the duration of AE signal is in millisecond level, and the duration of AE is 2 to 3 times longer than that of electromagnetic radiation. With the increase of loading rate, the duration of AE signal and electromagnetic radiation increase significantly, and the multiple increases with the increase of loading rate.

       

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