Sacoustic Emission Characteristics And RFPA Simulation Of Brittle Fracture Of Rock

The compression failure characteristics of rock with rock burst tendency and its monitoring technology are the basic problems of deep mining in mines.The granulite,granite and limestone as the research object,under uniaxial compression of rock AE test were analyzed,and different deformation characteristics of brittle rock strength on rock loading,AE frequency evolution characteristics of abnormal situation,and use RFPA to simulate the three kinds of rock AE evolution the characteristics,further reveals the brittle rock uniaxial compressive loading rupture characteristics of acoustic emission,the main research contents and results are as follows:1,Through granulitite,granite and limestone in uniaxial compression test of acoustic emission of rock strength and deformation,from two aspects of brittle rock uniaxial comprehensive strength,elastic modulus and shear modulus of rock mechanics parameters and deformation index analysis,summarizes the brittle rock breaking three basic forms and under uniaxial compression destroy the three basic stages of experience.2,Rock acoustic emission based on the theory,the specific analysis of the metamorphic rock,granite and limestone were under uniaxial compression loading rupture evolution characteristics of AE parameters,and find out the abnormal characteristics during failure in rock yield point or peak stress near the AE cumulative counts will suddenly increase also,the growth rate will rise sharply,the AE activity is extremely active,AE energy surge.3,The uniaxial compression loading granulitite,granite and limestone fracture frequency spectrum characteristics of acoustic emission in the detailed analysis and research,find out its characteristics and evolution in the rock abnormal findings: near the brittle,falling or rising abnormal abnormal signal energy entropy of EMD rock acoustic emission peak frequency of the majority;the acoustic emission signal is maintained at [43.95~92.77KHz],can set the bandwidth in general shows scattered by the concentration characteristics of acoustic emission signals;most of the rock acoustic emission signal before the peak frequency usually appear abnormally low phenomenon,and the acoustic emission signal can set bandwidth may appear abnormal phenomenon of expansion.4,The granulite,granite and limestone under uniaxial compression,acoustic emission are studied using RFPA simulation,the results showed that RFPA can well simulate the uniaxial compression element of rock failure and crack propagation and evolution of acoustic emission,simulation results and experimental results are in good agreement;in the explicit crack frontsimulation of acoustic emission,the abnormal aggregation phenomenon,and in damage,mainly in tensile AE;the displacement vector rupture location of bands appeared in chaos in the model,and the stress vector formed band network and crack propagation is consistent;simulation of acoustic emission cumulative count curve appeared later than the time of abnormal rise simulation of load curve abnormal decline time,can be used as a model of failure precursor information.