Study on Acoustic Emission Energy Characteristics of Rocks with Different Brittleness

The conventional uniaxial test for four kinds of rocks with different brittleness is carried to obtain the acoustic emission energy characteristics of rocks with different brittleness.In the process of loading,the acoustic emission(AE) signal is detected by the acoustic emission detection system.Stress-strain curves and acoustic emission energy curves are gotten from this test.The results show that the brittleness of samples increase with the increasing of the sand ratio.The stress-strain curve shapes of the samples are similar and there are no obvious plastic stages before the peak value,while the acoustic emission curves have the obvious plastic stage and the plastic stage becomes shouter as the brittleness increases.The acoustic emission energy reaches the maximum value at the peak value and the maximum value follows a power function relationship with the brittleness index of the samples.After the peak,the stress decreases at a moment,but the acoustic emission energy will last for a short time and the duration of acoustic emission activity is shortened with the increasing of sample’s brittleness.