A Study Of Nonlinear Dynamics Modeling For Commercial Vehicle And Ride Simulation And Analysis

Vehicle dynamics simulation has a wide array of application in the development of vehicle technology. Vehicle dynamics simulation can reduce the duration and costs during the research and development stages of cars. Therefore it is of significant importance to study the methodology for vehicle dynamic modelling.This paper aims at researching of general dynamic modelling methods for commercial vehicles. The leaf spring modelling is focused and the differences between the rigid-body vehicle model and rigid-flexible coupling vehicle model are emphasized. The major activities include:As the leaf spring is a key nonlinear component in commercial vehicle suspension, several modelling methods for nonlinear leaf spring are studied and compared. The SAE three-link model is chosen to be applied into commercial vehicle model. The parameters of the leaf spring are identified thorough an inverse method in conjunction with an optimization approach. The SAE three-link model is proved to be accurate and suitable for being implemented into vehicle dynamics, as its static stiffness, dynamic stiffness and installation stiffness are well matched with the test results.The rigid-body modelling approach for commercial vehicle is systematically researched, including the suspension system, steering system and powertrain etc. The flexible-body modelling approach for the chassis and cab is researched. The model reduction methods used to reduce the degrees of freedom of the flexible model are reviewed and investigated. Furtherly the rigid-flexible coupling modelling approach for full vehicle is studied. Finally both a rigid-body model and a rigid-flexible body model are established for the commercial vehicle.Dynamic simulations are conducted for both the rigid-body vehicle model and the rigid-flexible body model, including running over a single ramp a nd jumping down from platform. Both models are validated through the comparison between simulation results and test results. Moreover the accuracies of both models are compared. Finally the dynamic responses of the vehicle under the random terrain are predicted based on the developed vehicle models.This study concludes the general dynamic modelling methodology for commercial vehicle. The nonlinearity of leaf spring and rigid-flexible coupling characteristics of full vehicle are focused. This study can give directions for commercial vehicle modelling in multibody system models.