Research On Imaging Technology For Nodes Region Of Messenger Wire In High-speed Railway Of Railway Based On Bidirectional Time Reversal

With the high-speed railway has become an important means of transport, security has become a problem to be the primary consideration. The main bearing member catenary strand as electrification of railway catenary, the damage detection technology effectively is crucial. In this paper, " Research on Imaging technology for node region of Messenger Wire in High-speed Railway of railway based on Bidirectional Time Reversal" in the title, combined with ultrasonic wave and study time defect imaging technology combined with new inversion method for stranding structure is covered by a defective area is detected to provide new ideas, important academic value and practical significance.Research work is supported by the national natural science funding project(51305141), Guangdong province natural science funding project(2014A030313248) and Guangzhou technology plan project. This paper is organized as follow:(1)Analysis of the characteristics of ultrasonic guided wave propagation,and Its application to the detection of carrier cable covered by central anchor knot clip. The dispersion law of ultrasonic guided wave in the straight rod and screw was deduced. Draw the corresponding dispersion curves to determine the appropriate frequency of excitation signal(2) According to the existing shortcomings of time reversal, the focusing characteristics of bidirectional time reversal in slender structure was deduced. It proposes a defect imaging method combinated of ultrasonic guided wave and bidirectional time reversal.(3) The carrier cable conductor simulation model is set up by ABAQUS software. Through the simulation analysis of different modal guided wave in the transmission process of straight rod and wire and the defect of the modal conversion rule to select a longitudinal mode waveguide as a detection signal.(4) Proposed a method of separating a single mode waveguide in the acquired signal to be more accurate imaging, and explained how to achieve defect focus display. Imaging method was validated by establishing rod model, and the method used to detect the strands.(5) Finally, the above technology to test the object of round steel rods and messenger wire.The results show that the relative error of focus defects is less than 2.2%.