Study Of Electromagnetic Excitation Inftared Thermal Imaging Detection Method In Metal Parts Defect Based On Heat Transfer Analysis

This paper presents an infrared thermal imaging detection method based onelectromagnetic excitation for metal parts flaw nondestructive detection, this technologycombined the advantages of infrared thermal imaging detection technology and eddy currenttesting technology, it has a series of characteristics, high sensitivity, high efficiency,non-pollution, non-destructive, non-contact and simple operation. In this paper, the discussionwere studied though combining the theoretical research, numerical simulation andexperimental method.Analysis the advantages and disadvantages of conventional NDT detection methods inthe metal parts defect and the present research situation. Reviewed the research status ofelectromagnetic excitation infrared NDT technology both in domestic and abroad.Elaborated the basic theory of infrared detection, discussed the principle of infrarednon-destructive detection and summarized its method. Then point out the prominentadvantages of the electromagnetic excitation infrared nondestructive testing technology inmetal parts defect detection in this paper. Introduces the basic theory of electromagnetic fieldknowledge, and the3-D transient heat conduction is established based on the internal heatbalance condition of micro body in metal materials. Mechanism of electromagnetic inductionheating has been studied, and skin effect and penetration depth are given, the relationshipinduction heating process vortex type heat transfer and heat conduction type heat transferbetween the contact are analyzes in this paper.summarizes the energy loss in the heatingBased on the finite element analysis, establish the electromagnetic-thermal couplingfield calculation model to simulating the induction heating process. Through the numericalsimulation, the surface and the bottom temperature distribution and the heating temperaturevariation law with time. of metal plate. Simulation and analysis of the excitation time, currentfrequency and induction coil heating distance on the metal plate temperature control effect,and summarizes the influence factors on the effect of heating effect. This part of the researchprovide theoretical support for experiments electromagnetic excitation source optimizationdesign.Establish the typical defects finite element model of metal parts based on the scientificand reasonable assumptions, simplify the research model, boundary conditions and initialconditions and heat source function analysis the influence of simulation research in differentconditions. Under the condition of different defect size, depth and position, analysis the heatconduction process and temperature field distribution of metal parts defect by the infrarednondestructive testing. Determine the best time of the change rules of defect according to the sequence time imageThrough a simple experiment, proved that it is feasible of the infrared thermal imagingdetection method based on electromagnetic excitation...