【摘要】 利用MTS815材料试验机和12 CHs PCI-2声发射信号采集系统,对砂岩在等幅循环加载和分级循环加载条件下损伤破坏全过程的声发射规律进行了研究,探讨了Kaiser效应与Felicity效应,以及Felicity效应声发射中"明显增多"的尺度界定问题。试验结果显示:砂岩在试验中的Kai-ser效应显著,但有一定的局限性;当加载达到或超过其峰值强度的70%后,砂岩应力记忆特性中Felicity效应表现显著,Felicity比的演化显示出3个阶段特征,且总体呈下降的趋势;只要声发射"明显增多"的尺度范围设定合理,则对Felicity比的演化趋势没有影响。更多还原

【Abstract】 By using MTS815 equipment and 12 CHs PCI-2 acoustic emission acquisition system,the acoustic emission(AE) characteristics of rock under tiered cyclic loading and cyclic loading during complete failure process under uniaxial compression were studied,and the Kaiser effect and the Felicity effect and the standard of acoustic emission increasing obviously on Felicity effect were discussed.The results show that:the existence of Kaiser effect is valid,but it is bound and the upper limit of stress level under which Kaiser effect exists is 70% of the peak stress;after that,memory characteristic of rock stress shows obvious Felicity effect;the Felicity ratio presents distinct characteristics of 3 stages and decreases in general;there is no impact on the evolutionary trend of Felicity ratio as long as the standard of obvious acoustic emission falls in a appropriate range.更多还原