岩石类材料声发射事件的波谱分析

The spectrum analysis of acoustic emission signal in rock materials

对石灰岩和陶瓷试样分别进行了单轴抗压和围压实验,记录加载过程参数和声发射信号并进行了对比分析.结果表明,声发射现象与加载卸载能量突变有直接关系;利用小波分析可以有效地去除信号噪音,并实现信号的分解重构.对去噪后的信号能量谱密度进行分析,发现大能量声发射信号的能量谱密度与小能量声发射信号的能量谱密度存在明显的差异,这些差异基本上不随试样材料和加载方式变化.

The experiments of limestone sample's uniaxial compression and porcelain sample's confining compression were made respectively. The loading course and AE signals were recorded, compared with and analyzed. The results show that the AE event has direct relationship to the energy's abrupt change of loading and unloading process. With the wavelets tool, the noise of the AE signals can be cleared effectively, and the signals can be decomposed and reconstructed without information loss. The power spectra density(PSD) process of the de-noised signals indicates that large AE signals are quite different to that of small ones. And further more these difference vary little with the quality of material and mode of loading.