Research On Dynamics Modeling, Simulation And Optimization Oriented To Cross-wind Stability Of Bus

With much construction of the domestic highway, the actual vehicle speed is faster and faster. The effect of the cross-wind on the vehicle handling and stability, the security as well as the comfort become more and more important. The cross-wind stability of the vehicle gradually becomes one key problem which must be solved in the active vehicle safety research.Firstly, the thesis introduces the aerodynamic forces acting on the body of high-speed vehicle in theory. Then it is analyzed and obtained that the main natural factor affecting the vehicle cross-wind stability is the gust. The classification and the mathematical description of the natural gust are introduced. Lastly, the cross-wind type of this thesis is determined on the basis of the Zhengzhou wind speed data in 2010.The thesis chooses the air-suspension bus of one corporation as the research object. Based on the multi-body system dynamics theory and research method, the multi-body system dynamics models of the air-spring suspension, the chassis and the tire are separately built by the ADAMS/Car software. The seven discrete wind pressure centers of the chassis are taken into account and the cross-wind model with a shifting wind-pressure center are set up. The cross-wind simulation tests are carried out under different conditions by improving the standard of the crosswind sensitivity test stipulated on the American ESV. By comparing the simulation test results, the test data of the wind pressure center's shift is more reasonable.The influence of three type parameters is studied on the bus'cross-wind stability in consideration of pressure center's shift and some important parameters have been selected out in ADAMS/Insight. At last, the suspension optimization design is finished on the basis of the analysis result and some means improving the cross-wind stability are presented. It provides the valuable reference for the bus design and development.