摘要:
岩石受载破坏过程声电信号时域特征分析大多从声电信号幅值、振铃计数、能量等参数方面定性得出结论，并未直接给出声电信号时域相关性，且声电信号频域特征分析所用参数较单一。针对上述问题，开展了单轴压缩条件下岩石试样受载破坏过程声电信号监测实验，分析了岩石受载破坏不同阶段声电信号时频特征。结果表明：① 在压密阶段和弹性阶段，声电信号幅值基本为零；在加速破坏阶段，声电信号幅值逐渐增强，信号数量逐渐增多；在完全破坏阶段，声电信号幅值几乎同增同减，当载荷达到峰值时，声电信号幅值同时达到最大；在受载破坏全程，声发射信号幅值大于电磁辐射信号幅值。② 在加速破坏阶段，声电信号显著相关；在完全破坏阶段，声电信号高度相关；在受载破坏全程，声电信号随时间变化趋势基本相同，声电信号在时域上高度相关。③ 在加速破坏阶段和完全破坏阶段，电磁辐射信号以低频和甚低频信号为主；与电磁辐射信号相比，声发射信号频带更宽、主频幅值更大；声电信号主频集中范围相近但不完全一致；完全破坏阶段声电信号主频幅值大于加速破坏阶段声电信号主频幅值。
Abstract:
The analysis of time-domain characteristics of acoustic emission (AE) and electromagnetic radiation (EMR) signals in process of rock failure under load mostly draws qualitative conclusions from amplitude, ringing count, energy and other parameters, without directly giving time-domain correlation of AE and EMR signals, and parameters used in frequency-domain characteristics analysis of AE and EMR signals are relatively simple. In view of the above problems, monitoring experiment of AE and EMR signals of rock samples under uniaxial compression was carried out, and time-frequency characteristics of AE and EMR signals in different stages of rock failure under load were analyzed. The results show that: ① In compressionstage and elastic stage, amplitude of AE and EMR signals is basically zero. In accelerated failure stage, amplitude of AE and EMR signals increases gradually and the number of signals increases gradually. In stage of complete failure, amplitude of AE and EMR signals increases and decreases almost at the same time. When load reaches the peak value, amplitude of AE and EMR signals reaches the maximum at the same time. Amplitude of AE signal is larger than that of EMR signal in the whole process of failure under load. ② In accelerated failure stage, AE and EMR signals are significantly correlated. In stage of complete destruction, AE and EMR signals are highly correlated. In the whole process of failure underload, variation trend of AE and EMR signals with time is basically the same, and AE and EMR signals are highly correlated in time-domain. ③ In accelerated failure stage and complete failure stage, EMR signals are mainly low frequency and very low frequency signals. Compared with EMR signal, AE signal has wider frequency band and larger amplitude of main frequency. Main frequency concentration range of AE and EMR signals is similar but not completely consistent. Amplitude of main frequency of AE and EMR signals in complete failure stage is larger than that in accelerated failure stage.
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