Model Development of Automotive Air Spring Based on Experimental Research

In order to obtain the air spring characteristics, the static and dynamic experiments have been implemented firstly. The static stiffness and dynamic stiffness with displacement excitation frequency have been computed from the measured data. The dynamic experimental results show that the hysteresis in one displacement-force cycle becomes better when the frequency of the harmonic displacement excitation signal increases, but it does not change too much as the frequency is higher than 1Hz. And the dynamic stiffness goes up with increasing of the initial pressure and the excitation frequency. And then, based on the air spring experimental research, the mathematical model of the air spring is constructed in light of energy conservation. The static stiffness with different initial pressure is obtained by using calculated effective area from the static experimental results. The calculated static stiffness is accordance with the experiment results. By introducing equivalent damping, the dynamic model of the air spring considering hysteresis is constructed. Simulation results accord with experiment, which shows the equivalent model of the air spring is feasible.