Research on rigid-flexible coupling dynamics modeling for rack vehicle

In order to address the challenge of quantifying the impact of changes in slope and driving speed on individual components of rack vehicle, which is not feasible through experimental methods in practical engineering. Thus, based on the vehicle-track dynamics theory, this paper establishes a rigid-flexible coupling dynamics model of rack vehicle, which consists of vehicle submodel, track submodel, and gear-rack transmission model. In the model, the bogie frames are linked with the wheelsets through the primary suspensions and linked with the vehicle through the secondary suspensions, respectively, while three-dimensional spring-damper elements are used to represent the stiffness and damping characteristics of the primary and secondary suspension in three directions. Furthermore, regard the connection relationship between rack and sleeper as elastic damping, and the wheel-rail contact relationship is established on the nonlinear Hertz contact theory. Based on this model, the dynamic characteristics of rack vehicle are analyzed under various slopes and driving speeds. Results show that the slope has a substantial effect on the dynamic characteristics of each component of rack vehicle, whereas the driving speed primarily affects the root bending stress of rack and the vibration acceleration of gear. The research results is of great significance to the safety and stability of rack vehicle.