A three-dimensional airspring model with friction and orifice damping

This paper proposes a non-linear airspring model for general three-dimensional motions. The non-linearity stems from friction behaviour of rubber parts and from the air flow in the pipe between airbag and surge reservoir, in particular if the surge pipe is equipped with orifice damping. The model is based on superposition of elastic, friction and viscous forces. For a given preload the model has 6 and 7 parameters for horizontal and vertical motions, respectively. Comparsions between model and measurement results show good agreement for a wide range of cases. The model represents a reasonable compomise between accuracy and computational effort and should be a suitable tool in rail vehicle dynamics analysis.