Research on theoretical calculation model for dynamic stiffness of air spring with auxiliary chamber

Based on the theory of thermomechanics and fluid dynamics, the dynamic equations of air spring, auxiliary chamber and orifice were established, and then the calculation model for dynamic stiffness of air spring with auxiliary chamber was deduced. The model indicates that the dynamic stiffness of air spring is caused by the air spring effect area variation with air spring deformation, the air spring volume variation with air spring deformation, and the variation of air mass in air spring with air spring deformation. And the model is proved to be correct in test. Simulation model for dynamic stiffness of air spring was established under the Matlab/Simulink environment based on the calculation model and the dynamic equations of the components. Taking the Firestone 1T15M-2 air spring as example, the dynamics stiffness of air spring with varying parameters was calculated. The calculation results show that air spring pressure, the size of orifice, vibration frequency, vibration amplitude, volume of auxiliary chamber all affect dynamic stiffness of air spring, and the effect laws of the parameters on dynamic stiffness were analyzed in detail.