ANALYSIS OF THE VEHICLE-TRACK VERTICAL COUPLED DYNAMICS BASED ON THE GREEN'S FUNCTION METHOD

This paper presents a new method to analyze the vehicle-track coupled dynamics based on the Green's function method and the Non-linear Hertz's theory. By numerically solving the dynamic equations of linear systems of the vehicle and the track under pulsed excitations, the explicit expressions of the Green's functions of the vehicle and track systems were obtained. Subsequently, the characteristics of the Green's functions of the vehicle system and the track system were investigated, and the wheel-rail vertical forces as well as the vertical displacements of the wheelset and the rail were calculated under the excitations of track random irregularity and one single harmonic wave, respectively. The analyzed results of the new method were compared with those calculated from traditional methods. Results showed that the Green's function of the vehicle mainly consisted of two parts, describing the linear term and the attenuation term. The Green's function of the track attenuated as time increased. The initial pulsed excitation-induced rail vibration attenuated to 0 after 0.15 s. The calculated results using the Green's function method coincided well with those calculated from tradition methods, supporting the reliability of the new method.