ABSTRACT
Passenger railway vehicle secondary suspensions are often composed of a rubber spring in series with an air spring connected to a fixed volume reservoir. The behavior of the suspension is influenced by the presence of the rubber component at all times. This paper seeks to quantify this influence.
The elastomer model stems from the experimental results obtained by testing the isolated component. This component shows stress relaxation, viscosity, and low frequency hysteresis or friction.
The pneumatic component has also been tested without the rubber spring. The experimental data allowed us to determine polytropic indexes in each of these two elements, as well as study the flow through the restrictor that connects them both.
Both models have been simplified for combined simulation to assess the influence of the rubber component on the overall behaviour of the suspension for monochromatic excitations in a range of frequencies.
