Acoustic Emission Investigation on Crack Propagation Mode of Sandstone During Brazil Splitting Process

In the present work, the Brazilian tests for six sandstone samples were carried out. The acoustic emission (AE) method was applied to analyze the characteristics of the crack propagating mode and further to classify the cracking mode during the whole sandstone lump Brazilian splitting process. The study results showed that the AE event produced during the whole loading process, and different loading stages demonstrate different AE features. The amplitude of AE signals was increasing along with the loading stress, and there is a period of quiet time before the failure of the sample. It also concluded that more than 99% of the whole cracking signals are classified as tensile mode, and there are precious few shear cracks that occurred during the Brazilian test; the central frequency of the occurrence of the tensile crack is 138.58 kHz.