ABSTRACT
The transverse shakiness appears in car body when the railway vehicles are running in a low speed. Firstly, the rigid-body modes of railway vehicle are traced based on similarity recognition of Fuzzy Mathematics. And the changes of rigid-body modes with speeds are analysed. Secondly, the concept of modal coupling degree of vehicle system is proposed. In order to reduce the value of the coupling degree among the modes of the whole system, the parameters of the suspension system of the vehicle are optimized. The results show that carbody hunting occurs when the frequency of bogie hunting and the natural frequency of car body approach. The greater the mutual influence between the vehicle vibration modes is, the greater the degree of coupling is. The coupling degree of system can be reduced after the suspension parameter optimizes, so that the transverse coupling vibration can be weaken and the carbody hunting will be eliminated.
