The Design And Development Of Nondestructive Testing Instrument Of Barkhausen Noise

With the development of electromagnetic theory, Barkhausen technology matures, Barkhausen nondestructive detection method has been widely used in the measurements of ferromagnetic material fatigue damage, stress strain and so on. Based on the research of the Barkhausen signal, the main content of this paper was to build a friendly interface, easy to operate and can be real-time acquisition, display and processing of Barkhausen nondestructive testing instrument, and then test the existing experimental test.First of all, this paper expounds the importance of nondestructive testing technology and compared the Barkhausen nondestructive detection and the other five routine nondestructive testing of the advantages and disadvantages, emphatically introduces the Barkhausen nondestructive detection technology development status. In this paper, on the basis of research on Barkhausen noise detection theory, changes in that domain rotation and do main wall displacement is Barkhausen jump mechanism. This paper analyzes the influence of material properties and excitation voltage amplitude and frequency on the Barkhausen signal, and puts forward the Barkhausen signal analysis methods.Secondly, this paper completed the design of hardware and software of the Barkhausen nondestructive testing instrument. Hardware part introduces the selection of signal generator, power amplifier and the design of the excitation coil, compared the three kinds of magnetic sensor and the detection coil was chose based on the experimental result, signal conditioning circuit was built by AD620. The software part introduced the virtual instrument and its development environment— LabVIEW. The software was divided into five modules: parameter settings, system control, data analysis, the auxiliary function and the time domain analysis.Finally, a field experiment was conducted by Barkhausen detection instrument. Influence of excitation voltage and frequency of the MBN signal are analyzed, and on 45 steel and Q235 and 9CrSi three material is made of grooved specimen and tensile force after the 45 steel samples were tested, and compared its features in time domain value, frequency spectrum, envelope and pulse amplitude distribution.