Experimental Study Of Multi-Component Signals Of Rock Acoustic Emission

Most of the material in the process is affected by external factors deformed or broken, the phenomenon of acoustic emission will occur. Acoustic emission signal is the internal structure of the material changes in the release of a mechanical wave, which follows the general characteristics of mechanical waves, but also has its own unique acoustic emission signals characteristic features.In traditional acoustic emission experiments, although the acoustic emission signals emitted by different materials comparative analysis on the line, but only a single component were collected, the signal characteristics are manifested only a single component of the law, and can not be very effective comparative analysis. In this study on the basis of the two previous acoustic emission materials (sandstone and granite) acquisition of two components (vertical and horizontal) on acoustic emission signals, more comprehensive law reveals the characteristics of acoustic emission signals.Acquisition is an experimental acoustic emission requirements are very demanding on the experimental apparatus experiments, selection and performance of its instruments have a great request, that the instrument has high sensitivity, but also requires the instrument has good real-time monitoring and dynamic monitoring of performance. The experiment uses a more advanced virtual instrument technology in the Labview platform, using digital technology to32-bit digital signal processor-based, with high-speed analog/digital converter (A/D) and other relevant hardware circuit design into digital sound launch cards, these acoustic emission card into the appropriate slot on the PC, which constitute the digitized acoustic emission data acquisition and analysis system.In the analysis of experimental data, the background noise of the first experiment were analyzed to exclude the influence of noise on the analysis results, the influence of external interference in order to minimize the test results. Then the two methods were used to analyze the two types of comparative examples explain the similarities and differences more intuitive interpretation of acoustic emission signals and the similarities and differences between different rock rocks similar vertical component and a horizontal component. And the following conclusions:1. The horizontal component of the acoustic emission signal sandstone appeared later than the vertical component, but the corresponding rock compaction and crushing both obvious acoustic emission events.2. The vertical component and the horizontal component of granite maintain high consistency in the time domain, but in the late loading granite significantly exceeds the amplitude of the horizontal component of the amplitude of the vertical component.3. Start loading period, the number of acoustic emission events granite basically no, because Kaiser effect caused when pressurized by the stress is less than its historical stress, acoustic emission phenomenon does not occur. We also infer the existence of this pressure stage of sandstone, but because of its small subjected to stress, and therefore not reflected in the test.In this paper, the results of research and designed to solve the problem when strong directional signal detection using acoustic emission encountered, the acoustic emission signals in engineering applications to provide some theoretical guidance.