Abstract
This paper discusses how the vertical vibration character of bogie is affected by the nonlinear dynamic stiffness of secondary air spring. For this purpose, we have deduced the model of air spring by considering its inner construction and compressed air. Based on the measured data of dynamic stiffness of air spring, the verification of model has been done. A half-car model is used to compare the vertical dynamic performance with linear secondary spring and nonlinear air spring, respectively, and the difference of bogie acceleration among different spring models has been studied. The comparison results show that the domain frequency of vertical acceleration of bogie is affected significantly, but there is no clear change on the domain frequency of carbody. By further discussion, it is shown that the dynamic stiffness of air spring on bogie natural frequency is much higher than that of on carbody natural frequency.
