Modeling of Rigid-Flexible Coupling System Dynamics for Railway Vehicles with Flexible Bogie Frame

In order to study the influence of the flexible bogie frame on the vehicle system dynamic performance, the rigid bogie frame was replaced by the flexible bogie frame when the dynamic model was built. Based on the substructure method, the DOFs of the bogie frame finite element model were reduced by the Guyan method. When the results of full DOFs modal analysis were consistent with the results of reduced DOFs modal analysis, the rigid bogie frame in the dynamic model could be replaced by the master DOFs model. The dynamics results illustrate that it is feasible to build the vehicle system dynamic model by the rigid-flexible coupled method based on substructure method, and the flexible bogie frame possesses almost the same influence on the vertical vibration response of primary suspension and secondary suspension with the rigid bogie frame. But the flexibility of bogie frame affects significantly the vibration of itself and the lateral ride comfort of carbody.