The Multi-Body Dynamics Simulation Analysis, Optimization Design And Engineering Application Of IVECO Vehicle

Taking a type of IVECO vehicle as the research object , the dynamics simulation for the whole vehicle performance is studied by the Multi-Body System Dynamics in this dissertation. The optimization for the suspension system design is also investigated.The multi-rigid-body dynamics simulation model of the full IVECO vehicle is established. In order to improving the model accuracy, the flexible body models of the lateral stabilizer bar and the leaf spring are established using discretization method and modal analysis method, so that the multi-flexible-body dynamics simulation model of the full vehicle includes rubber bushings, flexible bodies and rigid bodies. The parameters of the full vehicle modeling are obtained based on blueprint look-up, experiment, calculation, and CAD modeling. It is fully proved by means of the road test and the simulation experiments of entire vehicle that our simulation model can predicate well the performances of dynamics.Using the simulation model, the dynamic performances of the suspension system of a type of IVECO vehicle are investigated. We obtained the curves of the camber-angle, toe-in angle, steerangle, and the vertical stiffness of the suspension with the change of the wheel center. We also investigated the relationship between rear wheel camber-angle and the body roll angle when the vehicle was in roll moving. The handling performances, ride comfort performances, and braking performances of this IVECO vehicle are all analyzed and the affective parameters for those performances are investigated. All those will benefit people when doing the improve design of this vehicle or designing a similar vehicle.In order to solve the problem of the ride comfort performances during the improve design of this IVECO vehicle; the optimization design of the suspension system of the vehicle is conducted. An optimization model and a set of optimization method based on simulation model are proposed. The optimization design of the suspension system of the IVECO vehicle is completed for 75 running cases. The optimization results have well improved both the vehicle ride comfort performances and handling performances because the model considersnot only the NVH of the suspension system but also the relative performance of the whole vehicle.The optimized suspension system has used in IVECO vehicle. The optimized suspension system has used in IVECO vehicle The road tests show that the ride comfort performances of the IVECO vehicle with optimized suspension system are improved greatly. The square-root of the acceleration at chair point has decreased about 18% in average in all speed conditions. The parameters of the optimized suspension system have no effect on the vehicle handling performance. In fact, it has improved a little for the steady-state steering characteristics and steering reversal characteristics. The optimization results have met the vehicle requirements at the best balance point.. The optimization model and a set of optimization method based on simulation model which is presented here have great value for the vehicle engineering.At last, software, ADAMS / IVECO, is developed for the suspension system optimization based on the ADAMS, which can be used for all IVECO vehicle or other vehicles with similar suspension system.