红砂岩变形演化及声发射主频特征实验研究.

The digital speckle correlation method was adopted to measure the deformation field.Acoustic emission information was monitored by acoustic emission system.This paper concentrated on acoustic emission characteristics of deformation field evolution of red sandstone rocks.By uniaxial compression,the deformation filed evolution,the correspondence between deformation filed evolution and acoustic emission dominant-frequency range and acoustic emission event rate,energy characteristics of acoustic emission dominant-frequency of red sandstone were studied.The results show that:At the start time of deformation localization,the low dominant-frequency acoustic emission events began to occur,then the number increased.The dominant-frequency distribution of acoustic emission events increased with the increase of dislocation rate.The quantity of low and higher dominant-frequency acoustic emission event rate are close,but the quantity is small.When the macroscopic crack developed of rock specimen,the low dominant-frequency event rate is larger.And the higher dominant-frequency event rate is smaller.At the peak of stress,the low dominant-frequency event rate is much higher than the high dominant-frequency event rate.The value of high and low dominant-frequency acoustic emission event rate is higher at the interface sliding stage.In the process of failure of rock specimens,the high energy acoustic emission events are mainly distributed in the low dominant-frequency range.Low energy acoustic emission events are distributed both in high dominant-frequency and low dominant-frequency range. [ABSTRACT FROM AUTHOR]