Simulation And Simulation Analysis Of Defect Eddy Current Of Titanium Alloy Sheet

Nondestructive testing has been developed for a long time, and its technical level has been improved day by day. Eddy current testing with its unique advantages has become a common technology in the field of industry. At the beginning of this paper takes electromagnetism development as an opportunity to gradually introduce the development outline of the domestic eddy current detecting technology. Aidding by AN SYS software simulation, figurring out effects of probe parameters, defects of titanium plate on the test results, modified a 3D simulation model test of titanium alloy defects.In this paper, the theoretical research contains:by means of the Maxwell equations and the electromagnetic field, the basic formula of the magnetic field is derived. Simplly understand the electromagnetic field boundary conditions, to grasp the common boundary conditions in ANSYS software. Taking the eddy current equivalent impedance circuit as the starting point, the impedance equation of the probe and the metal test piece is derived, and concludding the main factors that influence the change of the impedance of the probe.To study the relationship between the probe structure (inner diameter, outer diameter and height), the lift off of the probe, the frequency of excitation and the detection results, the two-dimensional finite element simulation model is built. Establishing 3D simulation model of eddy current detection:with the help of three-dimensional simulation model, respectively applied a sinusoidal voltage signal and pulse voltage signal to the excitation coil, to research of titanium alloy test correspondence between defects change and probe induced voltage; originally proposed for testing of titanium alloy sheet triangle array probe structure, explorring the defect size, quantity of induction voltage influence. When the relative position of the probe and the defect of the triangular array is changed, the change law of the induction voltage of each detector is studied.Through the above simulation calculation, promotting the study on the basic problems of eddy current testing:(1) using titanium alloy specimens as the object of study. It is proved that the specimen of the eddy current distribution caused by certain effect, the research for optimize the parameters of probe provides a reliable basis for (2) by means of three-dimensional finite element simulation model of titanium alloy surface defects are simulated and calculated, the obtained crack size change and induced voltage correspondence (3) proposed triangular array probe simulation model, the simulation analysis of the defects on the surface of the titanium alloy plate, and comparing different types of lack of depression (including the number, location, size, etc.) induced voltage of each probe to detect the effects of changes in the structure of the probe. By analyzing the simulation results, it is proved that the model is correct and practical.