Experimental Analysis of Sandstone Under Uniaxial Cyclic Loading Through Acoustic Emission Statistics

The aim of this study is to assess the evolution of acoustic emission (AE) energy distribution and acoustic emission waiting time of sandstone under uniaxial cyclic loading. Experimental study was conducted to collect AE data for this purpose. The uniaxial cyclic loading test results were statistically analyzed to determine the change in the AE energy distribution as the number of loading cycles increases. The outcomes of this study show that the relationship between energy distributions of acoustic emission signals, P(E), and the absolute energy level can be expressed by a power law where its exponent, ε, changes as the number of cycles increases. Close to the failure stage, ε decreases sharply as the number of cycles increases in accordance with the mean field theory. Furthermore, the existence of temporal correlations was studied by the waiting time and it reveals the existence of acoustic emission signals clustering also in power law (characterized by τ). The evolutions of ε and τ identify a way to signal cyclic loading collapse for brittle material before the sudden disaster failure.