Preliminary Exploration Of Influence Factors And Mechanisms In Fine Sandstone AE Event Space Positioning

Acoustic emission space positioning technology has been very widely used and acoustic emission system is sensitivity high, however, there are many influence factors is not yet systematic research.In view of this in order to improve its accuracy,using the rock mechanics loading equipment and acoustic emission monitoring equipment with fine sandstone in mianyang, sichuan as the research object.It is systemic researched through the end effect, moisture loading rate and load rate of three groups of specimens for research on the effects of acoustic emission events spatial orientation. At the same time, using scanning electron microscope (SEM) with different loading rate under the condition of sound emission area and silent launch events produce regional fracture were scanned, it can get a preliminary analysis of rock acoustic emission events under the conditions of different loading rate generation mechanism.End effect of influencing factors show that:end effect obvious specimen damage form is given priority to with shear failure, end effect is not obvious in the specimen is given priority to with tensile failure. End effect is obvious and end of acoustic emission events and active acoustic emission events will be ahead of time, specimen gap exist in acoustic emission events, blank area is often damaged serious area. Combined with paper gaskets and antifriction agent on the lower end effect and cut off the noise press effect is remarkable.Water as influencing factors, a saturated moisture content for the standard moisture content in dry state,25%,50%,75%, and saturated specimens tested. The results show that:with the increase of water content, uniaxial compressive strength of the specimens and wave velocity decreases, and specimen completely destroy the time-consuming, acoustic emission events peak lags behind, and with the increase of water content (reduce) the time lag larger (smaller), spatial distribution of acoustic emission events are more evenly.Put loading rate as influencing factors, with0.002mm/s,0.004mm/s,0.006mm/s,0.008mm/s,0.010mm/s loading rate. The results show that:with the increase of loading rate, uniaxial compressive strength of the specimens, acoustic emission events accumulative frequency decreases, and acoustic emission events in accelerated phase growth rate increases. Based on the different conditions of loading rate, silent launch events have an electron microscope scanning experiment area, With the increase of loading rate, audio launch event area specimen damage crystal clear, silent launch event area specimen crystal damage morphology changed little.