Based On Electromagnetic Ultrasonic Detection Technology To Research Thermal Stress On Railway

Rail temperature stress will cause railway bending deformation and safety accidents. Non-contactinspection of rail temperature stress has very high application value. This paper studies the method ofelectromagnetic ultrasonic to detect temperature stress. Because the electromagnetic ultrasonicdetection is performed in the skin layer of the surface, does not require a coupling medium, smallinterference from outside, strong environmental adaptability, therefore the electromagnetic ultrasonicmeasurement of the rail stress has a very broad application prospects.Based on the brief analysis of electromagnetic ultrasonic testing stress principle, derived thecorresponding stress testing at all stages of the equations of physics. And the detection system isdivided to ask for the transmitting module and receiving module.This paper use software Comsol to simulate the electromagnetic ultrasonic emission part. Duringthe simulate process, the research study on the transmitting coil, the distance between coil and railway,the strength of the magnetic field and the material of platform. Through the simulation results, weoptimize the platform structure and improve the system stability at last.According to the characteristics of the electromagnetic ultrasonic signal, the experiment designlock-in amplifier circuit for signal conditioning of the electromagnetic ultrasonic. Because of theelectromagnetic ultrasonic power is larger, it will produce electromagnetic interference to thereceiving module. Therefore, this paper studies the electromagnetic shielding technology, taking theshielding and other measures, and greatly reduces the influence of electromagnetic interference.This paper has completed the design of the electromagnetic ultrasonic detection system, and therail stress test, using the fitting method to get the stress phase difference between rails, laid thefoundation for dynamic detection of rail stress.