Acoustic Emission Monitoring of Rock Specimens During Fatigue Tests

Some of the most significant civil and historical structures, such as bridges, viaducts, dams and ancient monumental buildings, may collapse below the critical loading conditions due to fatigue effects. In the present paper, damage level evolution during fatigue tests of rock specimens will be evaluated by Acoustic Emission technique (AE). The fundamental parameters of AE will be analyzed in order to interpret the damage level evolution. The relationships between the cumulative AE counts and the damage accumulation during fatigue experiments will be considered for different kinds of iron-rich rocks (granite, basalt, magnetite). The achievement of critical conditions will be recognized through synthetic parameters based on AE, such as the b-value of the Gutenberg-Richter law and considering the increase in low-frequency components during the damage accumulation.