An Efficient Energy Method for Vibration Modelling and Analysis of Vehicle System With Three-Dimensional Elastic Carbody

To overcome the spatial limitations of traditional beam models in describing the one-dimensional vibration of trains in a plane, a train carbody model composed of six plate structures is established based on the energy method and moderately thick plate theory to accurately describe the three-dimensional vibration characteristics of trains in space. To better simulate the real state of the actual carbody, the door and window structures of the carbody, as well as the seat facilities on the inner floor of the train, are considered. Virtual springs are introduced to simulate the connections between different carbody walls. Subsequently, the energy functional is derived using the first-order shear deformation theory (FSDT), and the unified solution of the three-dimensional elastic carbody system model is derived using Hamilton's principle. Then, to validate the accuracy of the proposed method, four aspects of validation are performed including numerical convergence analysis, comparison with published literature, and correlations with finite element results and SIMPACK data under various operating conditions. Finally, a detailed parametric study is conducted on the vehicle system, such as the influence of window size, door size, seat position, seat quantity and seat layout on its vibration characteristics. The research shows that different parameters have different effects on the vibration characteristics of the vehicle system, and this facilitates lightweight optimization and targeted regulation in train development.