Acoustic emission characteristics and stress release rate of coal samples in different dynamic destruction time
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- 作者：Fukun Xiao ; xiao_fukun@163.com" class="auth_mail" title="E-mail the corresponding author ; Gang Liu ; Ze Zhang ; Zhiliang Shen ; Fengrui Zhang ; Yifei Wang
- 关键词：Dynamic destruction time ; Acoustic emission ; Outburst-proneness ; Stress release rate
- 刊名：International Journal of Mining Science and Technology
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：26
- 期：6
- 页码：981-988
- 全文大小：1398 K
文摘
Considering the importance of the prediction of rock burst disasters, and in order to grasp the law of acoustic emission (AE) of coal samples in different dynamic destruction time, the SH-II AE monitoring system was adopted to monitor the failure process of coal samples. The study of the change rule of the AE numbers, energy, ‘b’ value and spectrum in the micro crack propagation process of the coal samples shows that as dynamic damage time went by, AE presented high-energy counts and the accumulated counts increased during the compression phase. The AE energy and cumulative counts increased during the elastic stage. The AE blank area increased gradually and the blank lines were more and more obvious in the molding stage. The AE counts and energy showed a trend of decrease in the residual damage phase. AE ‘b’ values gradually became sparse, and the large scale cracks percentage compared with micro cracks decreased and the degree of damage decreased. The AE frequency spectrum peak went from the residual damage phase to the molding phase, and finally it was nearly stable, besides the bandwidth of the main frequency is gradually narrowed. Also, the frequency peak changed from single peak frequency to bi-peak frequency and to the single peak frequency. Uniaxial compressive strength is more sensitive than the elastic modulus to dynamic damage time.