Study On The Electromagnetic Acoustic Emission Mechanism And Numerical Analysis

Electromagnetically acoustic emission detection technology is a new non-destructive testing technology in recent years.It produces the Lorentz force excitation emission by local electromagnetic loading of the metal material to realize the detection of the defects of the conductor material and determine the equipment or components,so the study of electromagnetically acoustic emission technology in the practical application of the project has a very important significance.In this paper,the mechanism of electromagnetically acoustic emission is analyzed theoretically.The finite element analysis software is used to analyze the electromagnetically acoustic emission model of 3D electromagnetic field.Based on the experimental platform,the electromagnetic interference of different sizes is carried out.Acoustic emission experimental study,to complete the aluminum plate crack electromagnetically acoustic emission detection and evaluation methods.The main research contents are as follows:1.According to the electromagnetism electro-eddy current principle,we analysis the electromagnetic field analysis of the hollow cylindrical coil,and the mechanism of the electromagnetically acoustic emission is analyzed by combining the mechanics and the acoustic emission technique,and obtain the mathematical model.2.The parameters of the electromagnetic excitation system were designed by COMSOL finite element analysis software.The parameters of the optimal excitation coil and the parameters of the electromagnetic excitation were determined,and the crack of different sizes was simulated,and the influence of the change of crack length and crack depth on the electromagnetic excitation effect is analyzed.3.Based on the EMAE experimental platform,the experimental study on the electromagnetic acoustics emission of different sizes of cracks is carried out.The signal processing and information mining are carried out by means of characteristic parameter analysis,spectrum analysis and wavelet packet analysis.The main acoustic emission characteristics features and waveform parameters can be obtained for EMAE test.4.The EMAE experimental signal is decomposed and reconstructed to obtain the acoustic emission waveforms which characterize the defect characteristics,and the typical AE parameters are reconstructed according to the waveform.Then the evolution of characteristic parameters is determined with the crack length and the crack depth.And the electromagnetic acoustic emission detection and evaluation method of aluminum plates with different crack sizes is achieved,which makes the foundation for engineering applications.