通过砂岩试件疲劳破坏的声发射实验,分析了砂岩疲劳破坏过程的声发射特性,研究了岩石的疲劳损伤演化规律.按岩石整个疲劳过程的声发射特征及损伤演化规律,并参考岩石不可逆变形发展的三阶段规律可以将其分为四个阶段.岩石疲劳损伤破坏具有突发性,在岩石失稳阶段损伤加速演化.如果以声发射监测和预测岩石疲劳破坏,在损伤量0.4左右即进入失稳阶段,在损伤量0.3左右即进入失效阶段.
Acoustic emission (AE) characteristics of a sandstone sample in fatigue failure process were analyzed by AE testing and its fatigue damage evolution rule was studied. Based on the AE characteristics and the damage evolution rule, in consideration of the three-stage rule of irreversible deformation development of rock, the whole fatigue process can he divided into four stages. Fatigue damage failure of rock has the burst characteristic, and the damage accelerates to evolve in the failure stage. Experiment results show that, if rock's fatigue failure is monitored and forecasted by AE, it enters into the failure stage when the damage amount is about 0.4 and into the disabled stage when the damage amount is about 0.3, respectively.