Study on Stiffness Characteristics of Rubber Springs for Rail Vehicles Based on Different Constitutive Models

［Objective］ The structure of rubber spring shock absorbers for rail transit is complex, its stiffness characteristics are mainly predicted by simulation methods, but simulation results of different constitutive models vary greatly. The Yeoh, Mooney-Rivlin and Ogden three strain energy density function models of hyperelastic rubber materials and their applicable scenarios are compared and analyzed. Using the primary rubber spring in the bogie of rail transit vehicles as the research object, the installation methods, functional characteristics, structural composition, and performance requirements are expounded, the best from them are selected. ［Method］ A finite element analysis method for the static stiffness characteristics of primary rubber springs is established. The fitting effectiveness and computational accuracy of three constitutive models for hyperelastic rubber materials are evaluated using the fit of force-displacement curves and stiffness deviation as assessment metrics. ［Result & Conclusion］ The results show that the deviation between the simulated values calaclated using the Yeoh model and the experimental values is significant, follow by deviations of Mooney-Rivlin matel and Ogden model, but both the fitting effect and the computational accuracy of Ogden model are optimal. Therefore, the Ogden model is more suitable for analyzing the mechanical performance of the static stiffness characteristics of primary rubber springs in rail transit vehicle bogies.