周期性循环载荷作用下岩石声发射规律试验研究

声发射是岩石等脆性材料内部损伤的伴生现象。在周期性循环载荷作用下通过改变不同应力幅度和不同加载速率对细粒砂岩进行声发射试验研究，探讨了声发射在周期性载荷作用下的声发射规律。研究结果表明，改变上限应力对声发射现象的影响显著，而改变下限应力的影响主要在循环末期，提早了每个循环声发射产生时间；加载速率的增加提高了声发射率，特别是循环过程中主裂纹的形成和扩展阶段，加快了岩石破坏进程；不同应力幅度和加载速率下声发射表现出不同的发展模式，不同模式预示着不同的岩石变形破坏速率。

Experimental research on acoustic emission rules of rock under cyclic loading

The damage process is accompanied by the acoustic emission (AE) for brittle materials such as rocks. AE rule of fine sandstone was investigated under cyclic loading at different loading rates and different stress ranges. The research shows that changing upper limit stress has strong effect on AE rules, and changing lower limit stress advances the time of AE at the end of cyclic loading. Increasing loading rate makes the AE rate bigger, and accelerates the process of rock failure, especially, when the main crack is forming and expending. AE has the different changing mode at different stress ranges and different loading rates, which indicate the different deformations and failures rates of rock.