Research On Coach High Speed Waving Based On ADAMS

The character of vehicle handling and stability is one of the most important performance indexes. The problem of waving is the concrete manifestation of vehicle handling and stability during engineering application. In allusion to the phenomenon of waving during vehicle driving at a high speed, researches of waving problem have been made applying virtual prototype technology in a serious manner. Orthogonal DOE (design of experiment) optimization has been carried out considering vehicle simulation.1. Based on the two-degree-freedom system of vehicle, the performance of the two degrees of freedom's system included angle input and force input is analyzed with the aid of establishment of mathematic model, and then the relationship between the relative damping coefficient and parameters of the coach is studied qualitatively. Considering the effect of aerodynamic lift in the case of high speed motion, the cause of waving problem is studied scientifically.2. The coach body model with the ratio of 1:1 is set up with assistant of CATIA. The grid and boundary condition are generated with the software of Gambit. The lift coefficient and drag coefficient are got based on the simulation applying Fluent. In the paper, the RNG k ?εturbulence model is used as turbulence model, and the second order upwind is used as discretization scheme. The SIMPLE method is used to iterate.3. Based on the characteristic of handling and stability and the vehicle configuration, the 3D model of the coach is created successfully with the aid of ADAMS, which includes front anti-roll bar, suspensions, steering, tires, powertrain, body etc. With various vehicles designed, experiments that include high speed returnability test, single lane change test and steering wheel angle step input test are carried out, and effects on the yaw rate are got when the parameters change.4. According to the simulation, signification parameters are determined. Orthogonal DOE optimization went forward with the aid of ADAMS/Insight. The orthogonal DOE introduces four factors, two levels, eight tests. With the analysis of optimization, a optimal team included four factors is put forward. The validity of optimization is verified by simulation comparison, and also the vehicle handling and stability is improved, then the waving phenomenon becomes weak.