Dynamic analysis of secondary suspension system of railway vehicles with inerter

Abstract A vertical nonlinear dynamic model of a railway passenger vehicle is established, considering a quarter-car body, a half-bogie frame, and an inerter element. The bifurcation behavior and chaotic evolution of the system under varying excitation frequencies are investigated through numerical simulations. The results indicate that as the excitation parameter increases, the system sequentially undergoes single-period, multi-period, quasi-periodic, and chaotic motions, exhibiting typical nonlinear dynamic characteristics. To verify the theoretical model, an equivalent electrical circuit model is constructed on the Simulink platform based on the electromechanical analogy principle. Analysis of the phase portraits and time histories shows good agreement between simulation and numerical results, effectively reproducing the dynamic transition from steady-state to chaotic motion. Further comparison with a conventional nonlinear suspension system demonstrates that the inerter-equipped suspension provides superior vibration suppression and enhanced dynamic stability, highlighting the significant role of the inerter in improving the dynamic performance of the vehicle system.