热损伤大理岩声发射特性试验研究

Experimental study on acoustic emission behavior of thermal damaged marbles

对经历过不同高温作用的大理岩进行单轴压缩试验,并监测其全过程的声发射现象,用声发射撞击数研究热损伤大理岩的渐进破坏过程,得到经历不同高温大理岩的应力-应变曲线和声发射参数随应变变化曲线。试验结果表明:随着岩样经历温度的升高,岩样应力-应变曲线向扁平状发展,物理力学性质劣化程度变大;高温后岩石的声发射现象与常温有明显区别,热损伤导致试样加载初期声发射信号比较活跃,而进入弹性阶段后,声发射信号不如常温下剧烈。这些结果有利于更好地解决工程实际问题。

In order to study the influence of high temperature on the damage progressive failure of marbles,uniaxial compression experiments of marbles after different high temperatures were carries out,with acoustic emission(AE)system monitoring the whole progress.We obtained the samples’uniaxial stress-strain curves and the relationships between AE parameters and uniaxial strain.The higher temperature a sample undertook,the flatter the stress-strain curve was.And the mechanical property deteriorated more great.The results showed significant differences in the AE Characteristics between the samples at room temperatures and the samples after high temperatures.Because of the damage resulted from the high temperature,there were active AE signals when starting loading.And the changes of activities of AE signals wasn’t great after the stress going into the elastic stage.These results can provide guidance to better solve practical engineering problems.