Research On Acoustic Emission Of Damage Of MgO-C Refractory Under Compressive Load

Refractory material is an important supporting materials essential for iron-making,steel-making, casting and other industrial production of lining structure. Aiming at the problemof microscopic damage mechanism of damage process of refractory materials at roomtemperature under compression, using acoustic emission technique to obtain the damage signal,study the features of acoustic emission signal and the corresponding microscopic phase, studythe microscopic damage mechanisms of refractory material loading injury put forward effectivemethods. The main research contents include:1.Through the MgO-C refractories specimens subjected to uniaxial compression test, theacoustic emission technology to detect material compression injury of the acoustic emissionsignal and the damage process records, found the material loading damage can be divided into:the initial damage, damage propagation, sharp injury in three stages, the final specimen failure.2.By using the method of wavelet transformation to decompose the acoustic emission signal,using wavelet energy coefficient, combined with the physical properties of different damagephases, looking for frequency characteristics associated with specific damage mechanism. Theresults show that the AE signal energy is mainly concentrated in the two frequency range,indicating the material at this time showed two different dominant damage mechanisms, providesan effective method for discriminant compression injury mechanism of MgO-C refractory.3.Using the empirical mode decomposition analysis of transient signal, the acousticemission signal is decomposed into intrinsic intrinsic component, are calculated in time domainand frequency domain feature values to construct characteristic matrix, using principalcomponent analysis to reduce the dimension of feature matrix, for description of maincomponents of acoustic emission signal, on the basis of this, using principal component as theinput parameters, combined with support vector machine classification of damage signal. Resultsshow that, by using this method, the classification results can be in good agreement with thescanning electron microscope, and provides a new idea for magnesium carbon refractorycharacteristics analysis of acoustic emission signals of loading.The proposed wavelet transform and energy coefficient method can be effectively used foranalysis and extraction based on frequency characteristics of acoustic emission signal; empiricalmode decomposition and principal component analysis can effectively reduce the dimension offeature matrix and damage divided based on the purpose, provides a new way of signalcharacteristics of acoustic emission for the damage of MgO-C materials.