Multi-body Dynamics Simulation Analysis And Optimization Of A Minibus

Taking a certain type of Donfeng Xiaokang minibus as the research object, the Multi-body System Dynamics theory and methods are used to research in vehicle performance simulation and analysis, as well as in suspension optimization method which is based on Dynamics simulation.The multi-rigid-body dynamics simulation model of the vehicle is established by using Vitual Prototype software ADAMS/CAR. In order to improve the calculation accuracy of the model, the flexible parts of the vehicle, such as the lateral stabilizer bar and leaf spring, are modeled by discretization and model analysis method. The multi-flexible-body dynamics simulation model of the full vehicle which includes rubber bushings, flexible bodies and rigid bodies is finally established. The parameters of the full vehicle modeling are obtained by blue print look-up, experiment, calculation and CAD modeling. The established databse could be used in the research and design of the same type of automobile.The kinematics performance and the layout of key hard points of the front suspension are studied in this thesis. The Design of Experiment (DOE) is applied to study front wheel alignment parameters. An objective function which controls the tolerance of practical front wheel alignment angles and set values under typical condition, and the method of combining the orthogonal arrays theory with DOE method in ADAMS are put forward. The front wheel suspension system is founded based on this method, which is utilized to optimize the design of front wheel alignment parameters. The advances and validity of this method is testified by comparing the results of simulation and rig test. The full vehicle handling stability and ride comfort maneuvers are simulated based on the established model under national standards, including steering wheel angle step input test procedure, steering wheel angle pulse input test procedure, pylon course slalom test procedure, steering efforts test procedure, return ability test procedure, steady static circular test procedure, random road input test procedure and pulse road input. The parameters setup, data processing and results evaluating are also in consistent with national standards and the optimization method is put forward by evaluating results.An entire database of virtual prototype minibus model is established to make the following simulation, analysis and optimization more convenient and effective. A more accurate and advanced simulation and test can be introduced on the basis of this thesis.