Damage progression and acoustic emission in brittle failure of granite and sandstone

This paper experimentally evaluates and quantitatively compares stress-induced damage progression and acoustic emission (AE) in granite and sandstone based on continuous acousto-optic-mechanical (AOM) observations. Experimental results reveal that the step-rise characteristics of the AE event rate preceding the entire macrofracturing process and the apparent white patching phenomena are the most significant acousto-optical evidences for process...