| The phenomenon of acoustic emission and electromagnetic Emission is a kind of two kinds of physical effects,which are stored in the rock,and the stored energy can be released by acoustic energy and electromagnetic energy.Research on these physical effects,mainly concentrated in the single carrier Emission characteristics of rock acoustic emission and electromagnetic aspects,and Synchronization Research of rock under different loading conditions of both the less.In order to investigate the different load of brittle rock fra gmentation exhibited sound electrical characteristics,this paper carried out different brittle rocks under uniaxial static pressure head,the tool under the action of dynamic and static loads crushing of acoustic emission and electromagnetic Emission test,according to the acoustic signal acquisition process of broken rock acoustic emission and electromagnetic Emission characteristics to carry on the discussion,then analyzed the brittle rocks under different loads by crushing characteristics and acoustic emission and electromagnetic Emission characteristic parameters.The main contents and conclusions are as follows:(1)The use of macro fracture mechanics theory analysis the influencing factors under static load and dynamic force tool intrusive rock under stress wave loading of the acquisition process,discusses the mechanism of emission load under the action of the breaking process of rock acoustic,acoustic emission rate and the specific relationship between the stress intensity factor,the crack length increment the analysis of the characteristics of crushing process;the electromagnetic Emission signal,discusses the relationship between the amplitude of electromagnetic Emission and property parameters of rocks,the electromagnetic Emission amplitude increases with the elastic modulus of rock,rock loading stress is bigger,but smaller amplitude of electromagnetic Emission;electromagnetic Emission is much larger than the amplitude trend with Poisson the increase of the ratio will increase with the elast ic modulus of the rock.(2)As the research object,the experiment of acoustic emission and electromagnetic Emission is carried out under the action of pressure head and cutter.The results show that the loading damage of acoustic emission and electromagne tic Emission signal changes with the difference of rock under the action of pressure head and the tool,when the rock failure,flat end indenter loading rock ring count rate and energy rate increased gradually with the increase of load,the electromagnetic Emission signal increases with load,and the tool is static penetration rate saltatory change ring count rate and energy of acoustic emission and electromagnetic Emission signal will appear surge phenomenon.(3)Comparative analysis of rock pressure head and the tool under the loading process of acoustic emission and electromagnetic Emission characteristics shows that: the load of acoustic emission and electromagnetic Emission in the process there was a positive correlation with the coupling relationship b etween loading rock,two have good correlation,can well reflect the rock deformation and failure process of electromagnetic Emission,but the ratio of signal of rock acoustic emission signal is much richer,appear too early,electromagnetic Emission than acoustic emission with broader mechanism.(4)Under static load,the initial loading of rock has a small number of acoustic emission and electromagnetic Emission signal,the failure process of different samples are accompanied by acoustic emission and elec tromagnetic Emission signal,but the strength of rock during the process of failure to accept the acoustic emission and electromagnetic Emission signal peak,different the sample between high energy events often corresponds to counting less,more often cou nting energy corresponding to small events,has a good relationship changes in the process of test the received electromagnetic Emission signal and the pulse number of time.(5)Under the dynamic loads,compared with a sample of acoustic signal,the peak and rock stress signal peak probably in the same time period,but the peak value of the electromagnetic Emission signal than the peak stress,the acoustic emission signal peak time earlier.(6)Comparative analysis of static and dynamic load test results of rock fragmentation data show that acoustic electric,acoustic and electric signals of each of the major representative of a jump rock breaking test process of acoustic emission,electromagnetic Emission signals can reflect the stress state of the sample w ell and deformation degree,fracture morphology and the sample is the acoustic emission monitoring technology can rock by electromagnetic Emission stress and damage,can play a role in the prediction of Engineering practice. |
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