Model for rubber springs in the dynamic analysis of rail vehicles

A non-linear dynamic rubber spring model is proposed. The model mainly aims at representing the mechanical behaviour of rubber suspension components in rail vehicles for the frequency range of 0-20 Hz. The model is one-dimensional with a relationship between force and motion based on a superposition of elastic, friction and viscous forces. Inclusion of a friction force means that increased stiffness at small displacement amplitudes as well as rate-independent damping (hysteresis) can be considered. The present model has five parameters. Comparisons between model and measurement results are carried out for harmonic excitations, emphasizing the stiffness and damping dependence on displacement amplitude and frequency. But a case with a harmonic excitation superposed on a ramp function is also illustrated. The model results show good agreement with the measurement results. The present model should therefore be a suitable tool in the field of rail vehicle dynamics analysis and simulation.