Research On Propagation Characteristics Of Ultrasonic Guided Wave In Rail

Railway transport has an important role in human transportation. With thepopularity of high-speed rail, more and more people choose rail to travel. To ensurepeople’s lives and property safety, it is particularly important to guarantee the safeoperation of the railway. Broken rail is one important factor which affect the safety ofrail transport, while it is urgent to develop detection technology of broken raileffectively. Existing detection technology which includes rail flaw detection car hassome disadvantage, which has a slow detection speed and detection inefficiently.Because ultrasonic guided waves have several advantages that could propagate in along distance and have an efficiency detection, which has a special advantage for raildetection. This paper conduct the propagation characteristics of ultrasonic guidedwave in rail, and main research work includes:(1) Calculating the propagation characteristics of ultrasonic guided wave in railusing numerical analysis based on the method of characteristic frequency. Based thetheory of the vibration modal, calculating dispersion relation of the global rail usingcharacteristic frequency, analyzing wave structures of typical guided wave modes inrail. Simultaneously calculating dispersion curves of rail head which belong to rail,then analyzing wave structures of typical guided wave modes in rail head.(2) Studying the propagation characteristics of surface wave in rail using apiezoelectric angle probe. Discussing the propagation of surface wave where surfacewave propagate on the head surface of rail head, in the web, on the bottom of rail.Experimental results show that, with the propagation distance increases, theamplitude of surface wave has a trend of oscillation attenuation.(3) According to the mechanism of electromagnetic ultrasonic, designed thesurface wave electromagnetic ultrasonic transducer. Using the transducer ofelectromagnetic ultrasonic transducer to conduct experiment tests with surface wavein rail, which verify the availability and practicality that electromagnetic ultrasonictransducer with the type of surface wave could detect rail.