Crack mode analysis of cement mortars with signal - based acoustic emission techniques


Determining the crack mode in structures made of brittle materials, such as concrete and masonry, is important for structural analysis and failure prediction. Fractures monitored with the acoustic emission technique (AE) are commonly classified into different modes using Rise angle (RA) – Average Frequency (AF) analysis, the simplified Green's functions for moment tensor analysis (SiGMA), and frequency spectrum analysis. However, the classification limits are dependent on the material, the test setup, and the monitoring condition. Hence, this study defines these limits by comparing the three AE-based fracture mode analysis methods on AE data collected from three test types on mortar specimens. In a direct tensile test, the peak frequencies of most of the AE events were higher ( >60 kHz). While almost all of the AE events in a friction test had significantly lower peak frequency ( 
