The propagation characteristics of flexural wave in periodic ballast track

Abstract

The vertical vibration band gap characteristics of the ballast track were investigated in this paper. The rail was simplified as a beam with double layer of periodic supports. The dispersion characteristics were studied considering the rail as Timoshenko beam, using the plane wave expansion method. The eigenvalue equation of the Timoshenko beam with complex boundary conditions, which was a problem for the traditional plane wave expansion method, has been solved using special mathematical solution of matrix inversion. The band gap of the flexural waves in periodic track structure was confirmed by the rail vibration transmission characteristics obtained from the experiments. The physical significance of band gap frequency was analyzed in detail in this paper. In addition, we give a more accurate prediction model of Bragg band gap frequency of periodic track structure compared previous studies. The band gap of the flexural waves in periodic track structure was confirmed by the rail vibration transmission characteristics obtained from the experiments. The influence of temperature force on the band gap characteristics of the flexural waves was also analyzed, and a sensitivity index of temperature force was given as a result. The results indicate that the square of the band gap frequency has a linear relation with the longitudinal temperature force, which is different from the previous research.