Numerical investigation of nonlinear properties of a rubber absorber in rail fastening systems

A nonlinear dynamic model of a rubber absorber in railway fastening systems is proposed, based on the superposition principle to simulate its nonlinear vibrational behavior. A dynamic experiment was carried out to obtain all model parameters. The accuracy of the model was supported by good agreement between measured and simulated results, and it should therefore be an effective mechanical tool for simulating and characterizing the nonlinear behavior of rubber absorbers in rail fastening systems at particular vibrational modes. Excitation frequency dependency and amplitude dependency of the nonlinear dynamic stiffness were also selected for further study. The results indicate that characteristics of the nonlinear dynamic stiffness are closely associated with both displacement amplitude and frequency, although frequency dependency is not as great as amplitude dependency.