摘要
为了获取圆柱状岩石样品在三轴压缩过程中的声发射活动特征,克服常规压力室加载结构和岩样外形对声发射传感器安装的限制,对岩石三轴压力室底盘进行结构改造。采用新结构的底盘能够较为全面地采集石灰岩三轴压缩变形中完整的声发射信号。借助Matlab软件自备的时频分析方法进行声发射参数特征及声发射频谱及时频变换分析。从得到的频谱分布点图与时频变换三维图可以看出>230 kHz的中低频段幅值较大,而>230 kHz的高频段幅值较低;在中低频段有相对集中的主频,约175～190 kHz及75～90 kHz。频谱分析结果表明,加载初期的声发射信号低频低幅值成分较多,而在破坏前高频(低幅值)和低频(高幅值)的幅值都有所增加。
In order to meet the requirement of the measurement of aeoustic emission activity of evlindrical limestone in triaxial compression. this paper improves the structure of lower plate of triaxial cell by overcoming the limitalions on both the structuer of cell and shape .f specimen. The acoustic emission activities of stressed limestone sample are fully recorded. Furthermore, information of AE is not only interpreted, but is analyzed using frequency-domai, and timedomain methods, h is shown thai amplitude of low-/medium-hrequency of AE less than 230 kHz is apparently larger than that of high frequency. Particularh, there is much frequency occurring at medium-/lower-freqtteney with 175 ~190 kHz and 75 ~ 90 kHz. The results indicate that low-frequency with low amplitude signals dominale acoustic, emission activitilies at initial loading, whereas both high frequency with low amplitude and low frequency with high amplitude, increase gradtlally.
出处
《实验室研究与探索》
CAS
北大核心
2013年第4期19-22,59,共5页
Research and Exploration In Laboratory
基金
国家自然科学基金青年基金项目(41202194)
山东省自然科学基金青年基金项目(E0409)
关键词
声发射
三轴压缩
频谱分析
岩石
acoustic emission
triaxial compression
spectrum analysis
rock
