Modeling and analysis of time-domain nonlinear characteristics of air spring with an auxiliary chamber

• A time domain model of the air spring with an auxiliary chamber (ASAC) system is developed and validated. • The proposed model disclosed the experimental phenomena of the orifice-type and pipe-type ASAC systems. • Key parameters determining the ASAC system step response are found. The paper aims to establish analytical models for air spring with an auxiliary chamber (ASAC) to study the nonlinear characteristics of ASAC systems in the time domain. A test bench is built for measuring the dynamic characteristics of an ASAC, and the transmitted force of an ASAC is measured if harmonic and transient step displacements are applied. To calculate the transmitted force of orifice-type and pipe-type ASACs, lumped parameter models are developed, and the transmitted force are calculated by using convolution theory. Based on the established models and the measured data, model parameters are identified. The relative error for estimating transmitted force response using the proposed model is less than 6.1% compared with experiment under harmonic excitations. The characteristics that the transmitted force of an orifice-type air spring is monotonically attenuated while that of a pipe-type one is oscillating attenuated under step excitation are explained in the view of physical insight using the proposed models. Finally, a one-degree-of-freedom vibration system that assumes the stiffness and damping is provided with the proposed ASAC model is used to study the transmitted force of the mass element if step displacement excitation is applied to the base. The effects of designed parameters on the transmitted force responses of the vibration system are analyzed.