Nonlinear characteristic analysis of gas-interconnected quasi-zero stiffness pneumatic suspension system:A theoretical and experimental study

Abstract

Since traditional air suspension system is limited to respond the greatly changed load of commercial vehicles, a new Gas-Interconnected Quasi-Zero Stiffness Pneumatic Suspension (GIQZSPS) is presented in this paper. Firstly, a nonlinear mechanical model including the dimensionless stiffness characteristic and interconnected pipeline model is derived for GIQZSPS system. The restoring force of suspension system is simplified by Taylor series expansion, which is brought into the motion differential equation and the steady-state response solution is obtained by using the harmonic balance method. Next, the influence of stiffness and damping ratio on the jump frequency is discussed, and the vibration isolation performance of GIQZSPS system is analyzed by adopting the force transmissibility rate as the evaluation index. Finally, a testing bench simulating 1/4 GIQZSPS system is designed, and the testing analysis of the model validation and isolating performance is carried out. The results show that the proposed GIQZSPS system in gas connected and disconnected states have the same natural frequency, and GIQZSPS system in the disconnected state has higher stiffness but is sensitive to load changes. Meanwhile, the proposed GIQZSPS system in the connected state has a higher resonance peak value and exhibits better vibration isolation at higher loads. Accordingly, the proposed GIQZSPS system can adjust the connectivity status according to different load conditions.