This study aimed to investigate the acoustic emission (AE) behavior of rock salt under combined creep and fatigue. The loading path was in a stress-controlled mode and contained a constant stress load with different durations, followed by cyclic loading. The AE counts, peak frequency, amplitude, b-value, and RA (rise time/amplitude)-AF (average frequency) distribution were systematically analyzed. The results show that the AE counts gradually increased during loading and existed sporadically within the prior creep stage and frequently in the subsequent cyclic loading phase. The peak frequency exhibited a zonal distribution and was divided into low, medium, and high parts. A longer prior creep duration induced a wider frequency distribution range, a higher average amplitude, and a reduction in b-value. According to the RA-AF distribution, the tensile cracks constituted more than 90% of the total cracks, and the prior creep duration decreased the shear crack propagation compared with the cases without prior creep. The results indicate that prior creep increases the crack dimensions and damage severity and makes the salt sample prone to fracture in the subsequent cyclic loading.

本研究旨在研究岩盐在蠕变和疲劳联合作用下的声发射 (AE) 行为。加载路径处于应力控制模式，包含具有不同持续时间的恒定应力载荷，然后是循环加载。AE 计数、峰值频率、幅度、b值和RA（上升时间/幅度） -AF（平均频率）分布进行了系统分析。结果表明，AE计数在加载过程中逐渐增加，在前蠕变阶段零星存在，在随后的循环加载阶段频繁存在。峰值频率呈带状分布，分为低、中、高三个部分。较长的先前蠕变持续时间导致较宽的频率分布范围、较高的平均振幅和b值的降低。根据RA-AF分布时，拉伸裂纹占总裂纹的 90% 以上，与没有先导蠕变的情况相比，先导蠕变持续时间减少了剪切裂纹的扩展。结果表明，先前的蠕变增加了裂纹尺寸和损伤严重程度，并使盐样品在随后的循环加载中易于断裂。