The Modeling Of Full Vehicle Dynamics Based On Rigid-flexible Coupled Method And Analysis Of Suspension Vibration Isolation

This dissertation was studied in the background of program of"Vehicle NVH Control", which is one sub program of"National 863 Project". Vehicle NVH performance, as an important indicator of regulation and factor of competition, has became more and more important in today's vehicle products. As a major component of vehicle, the suspension system can ease the impact and absorb the energy from the wheels. The geometry characteristics, stiffness, damping, rubber bushings of suspension are all extremely important roles in suspension vibration isolation and ride comfort of a vehicle.With the development of computer technology and numeric analysis theories, CAE technology plays an increasingly important role in the modern automotive product design. In order to consider the contribution from suspension to vehicle vibration isolation when designing a vehicle, this paper used finite element method and multi-body dynamics simulation of virtual prototyping technology to study the structural characteristics and parameters of suspension system on the impact of vehicle vibration. Firstly, normal mode analysis of some major structural components of suspension had been taken in order to obtain the vibration characteristic. Meanwhile, with the virtual prototype software ADAMS / Car, all subsystems, including the front/rear suspension, steering, tires, body, power train etc., were established. And then organize all subsystems to build a rigid-flexible coupled dynamics full vehicle model to improve the modeling accuracy.Secondly, dynamics simulation was taken to analysis the vibration isolation performance of suspension system in this paper, and a function to calculate the RMS of acceleration values was also written. On basis of above, using experimental optimization method to optimized the front and rear suspension stiffness and damping parameters of the suspension system, which resulted in improvement of suspension vibration isolation performance.Finally, consider rubber bushings to be the few parameters can be modified and their flexible connection function, using the FEM to analysis stiffness characteristics of rubber bushing and making sensitivity analysis of their contributions to vibration, to optimize the stiffness of some important rubber bushings, in order to provide guidance to improve vehicle vibration isolation.