The Acoustic Emission Characteristic Research Of Rock Sample Under Uniaxial Compressive Loading Condition

Rock is a typically inhomogenous brittle material which contains many natural weaknesses with various scales, such as microcracks, pores, and joints. large numbers of acoustic emission (AE) signals would be produced when rock suffer load till to failure.Because of AE signals are generated by propagating and expanding of microcracks inside rock, each AE signal contains plentiful information of structure changing inside the rock.This article studies based on the uniaxial compression loading test, with the characteristic of AE signals in loding process. Aim to establish mathematics model of relationship of crack damage stress threshold,peak stress and AE wave speed in the rock failure process. summarize acoustic emission activitie characteristics in failure process of the rock sample. At last, attempts to analysis the precursory features before rock failure under biaxial loading conditions. The main detail content of dissertation as follow:(1) Through experiment of Uniaxial Loading, analyse the acoustic emission activity characteristics by using the rock specimens in the course of the phenomenon of acoustic emission on the breakdown of the different stages of granite (compaction stage, the initial crack, crack growth and instability, etc.) by acoustic emission monitoring system.(2) By study the relationship between internal damage and acoustic emission in the rock failure process, studying rock damage evolution and the precursory features before rock failure under uniaxial compress condition, doing reliability analysis for the prediction of rock destruction by stress threshold.(3) By the analysis of axial strain, lateral strain, volumetric strain, crack damage stress threshold and AE hit rate, study the AE parameter feature at different stages of crack development and the feasibility of discriminating crack propagation situation within rock through multiple ways.(4) Based on AE technology and linear regression statistical method. analysis the relationship of crack damage stress threshold,peak stress and AE wave speed in the rock failure process.