Experimental And Numerical Studies Of Damage Detection In The Switch Rail Using Ultrasonic Guided Wave

Railway is one of the most important infrastructure in china. It’s also a public transportation which people can use conveniently. Therefore, there’s always a central position for railway among all kinds of transportation. Switch rail is an important component in railway. With the help of switch rail, trains can change the line where they are running. Because of the need of changing lines, the switch angle is always very large. So there’s always large impact on the switch rail and it will lead to defect generation. However, the current ultrasonic wave technic we used now cannot detect the damage in switch rail. So there is an urgent need to develop an effective switch rail damage detection method. Based on this need, this passage is mainly about the propagation characteristics in switch rail, which contain following content. This passage create a 3D model of switch rail based on type SC330, do numerical research in FEM using the commercial software Ls-Dyna. It analyze both the low and high frequency signal in switch rail, find out the suitable frequency of the frequency we should use. It also verifies the possibility for guided wave propagating in switch rail. Make different defects in 3D model, and use different frequency to detect damage in the way of FEM. Research shows that it is possible to detect damage in numerical simulation. The frequency used and the position of the piezoelectric patches will affect the results of defects identification. Design a set of defects identification experiment combined with the result of numerical simulation, use the P50 switch rail whose length is 5.25 m. Use all kind of frequency band guided wave to detect defect on the bottom and top of switch rail. Analyze all representative signals in detail, and find a suitable frequency band to propagate guided wave. Research shows that it is possible for guided wave to propagate in switch rail.