Study of Acoustic Emission in a Compression Test of Andesite Rock

In the compression test of a material's sample, elastic waves produced by dynamic processes are known as acoustic emissions (AE). These waves, which propagate from the source to the material surface, arrive to the piezoelectric sensor where they are converted to electric signs and transformed into the typical AE parameters. These parameters will be employed for the evaluation of failure mechanisms present in the test. In this work, the mechanic behaviour of andesite's rocks of Cerro Blanco, San Juan, Argentina was studied. Two compression tests were performed for two cylindrical rock samples and the AE parameters were measured. The measurement configuration consisted of two syntonized sensors at 60 kHz and 150 kHz placed on the lateral face of the sample. The AE parameters registered were amplitude, duration, energy, RMS, etc. This data group was related to the load–time curve. Different indicators like average frequency and the ratio of rise–time to amplitude of the signal were calculated. These indicators were analyzed and evaluated with the purpose of identifying the damage level and the type of failure.