Complex stiffness model of an air spring with auxiliary chamber considering inertial effects of gas in connecting pipeline

Abstract

In this paper, an analytical complex stiffness model of an air spring system with auxiliary chamber is established considering inertial effects of gas in connecting pipeline. The established model can reflect the resonance phenomenon of the dynamic stiffness curve due to the gas inertia in connecting pipeline as well as the amplitude dependent characteristic of the dynamic stiffness. To obtain the key parameters of the model, a finite element model of the air spring system and a CFD model of the pipeline are developed respectively, then relative simulation analyses are operated. The complex stiffness of air spring system is calculated and investigated with the proposed model. The calculation results are compared with that of the experiments and the existing complex stiffness model. It shows that the calculation results of the proposed model agree well with the experimental results. The proposed model is especially suitable for air spring systems with large pipeline gas inertia and low pipeline damping. Moreover, it is deduced that when the inertial effect of gas in the pipeline decreases and the damping of the pipeline increases, the proposed model in this paper can be transformed into the existing model. Thus, this new complex stiffness model has a wide application range.