Abstract: Considering mechanic characteristics of the rubber bellow, the bellow model is composed of friction model and fractional derivative Kelvin-Voigt model for representing amplitude dependence and frequency dependence of the bellow. Regarding air spring with throttling damping orifice and auxiliary chamber as the research object, A nonlinear model of air spring is established. Near the standard working height of the air spring (namely equilibrium point), a linearized model is set up by adopting the first order Taylor expansion and secant method. Taking an air spring as an example, the parameters of bellow model have been identified and the validity of bellow model put forward is verified by the experiments. Finally, this paper analyzes the dynamic characteristics of the system and discusses the influences of mechanic characteristics of the bellow on the dynamic characteristic of the whole system. The model provides the theoretical foundation and valuable reference for the further study of the design and match of stiffness and damping of air suspension.

Key words: Guangzhou 510640, South China University of Technology