液态CO_2相变破岩振动信号能量分布特征

Research on Energy Distribution Characters about Liquid CO_2 Phase-transition Broken Rock Vibration Signal

针对液态CO_2相变破岩,设计振动信号监测试验,基于小波包变换分析振动信号能量分布规律。结果表明:液态CO2相变破岩振动信号主振频带与振动信号方向及传播距离相关性较小,基本位于0~4 Hz子频带,但主振频率对应能量分布百分比随着传播距离增加逐渐降低。随传播距离的增加,垂向振动信号高频段能量百分比逐渐增加,低频段能量百分比逐渐降低,且在中高频附近出现与主振频带对应能量百分比逐渐接近的"子中心"频带。同一测点不同方向频率能量分布百分比在0~100 Hz频带存在一定差异,但在其他频域内基本一致。

The vibration signal energy distribution analysis of rock breaking by liquid CO2 phase transition is conducted based on wavelet packet transform under the designed test. The results show that the master frequency band of the signal has little relationship between the direction and propagation, and the frequency is among the 0 - 4 Hz sub-band. The energy percentage of the master frequency band decreases with the propagation. In addition, the energy percentage of high frequency band of the vibration signal increases gradually with the propagation, and decreases gradually in the low frequency band. The sub-center band arises in the vicinity of the middle and high frequency, and the energy percentage is close to master frequency band. The frequency energy distribution percentage in different directions has a certain difference in the frequency band 0 - 100 Hz,but it is almost the same in other frequency band.