Abstract: Considering the rail as an infinite Timoshenko beam supported by two spring-damper layers, the vertical vehicle-track coupled dynamic model is established in frequency-domain. Green’s function method is applied to solve the partial differential equations of the rail. The dynamic response of rail can be calculated in wide frequency band without any limitations due to modal truncation. The point and transfer receptances of vehicle are obtained with its dynamic equations. Real track irregularities spectrum is used as input with pseudo-excitation method to get the random vibration response of both track and vehicle in coupled system. And the results of three different models – flexible track, rigid track and simplified spring track are compared. Results show the frequency response of this Timoshenko beam rail model can be gotten efficiently with Green’s function method. With pseudo-excitation method and superposition method, the response can be calculated on the condition of wheel-rail multi-points contact. Rigid track results in overestimating vibration for vehicle model in high frequency region. The system is sensitive about vehicle speed. The track model including the influence of its flexibility is more realistic. Green’s function method is fast and accurate for solving this problem.

Key words: vertical vehicle-track coupled model;Timoshenko beam rail;Green’s function method;random vibration