Characteristics of Acoustic Emission Caused by Intermittent Fatigue of Rock Salt

This paper compares classic (continuous) fatigue tests and carried out with time intervals of no stress in rock salt using a multifunctional testing machine acoustic emission equipment. The results show that have strong impact on the activity salt. In intervals, residual strain circles following an interval (α circles) is generally larger than before (β circles). insertion process accelerates accumulation strain: longer interval, faster accumulates during shorter life α produce greater number counts β circles, which demonstrates leads to internal structural adjustment mesoscopic scale. During stress, becomes more active because reverse softening caused by Bauschinger effect, plastic deformation. A qualitative relationship between accumulated damage variable established. threshold duration exists (around 900 s).