A Passenger Car Suspension K & C Characteristics Analysis And Its Matching Research

Suspension system is one of most important component of chassis and its K&C characteristics have a direct correlation with vehicle handling and stability, which has an important influence on vehicle performance during the development of the chassis, so, how to reasonably match the KC characteristics of suspension is the key to improve vehicle performance. This paper based on a passenger car chassis development project, front and rear suspension model are established and carried out analysis by Adams/Car, the suspension performance rationality of the R&D model is analyzed by reference to benchmark car, and the irrational existed in model is optimized. The result show suspension characteristics have been improved and better than benchmark car performance. The better steady turning performances of the vehicle are obtained in final.The suspension rigid-flexible coupling model is constructed by multibody dynamics in this dissertation, torsion beam and stabilizer bar flexible model was established based on modal synthesis method using Hypermesh, Patran. And then modal neutral file using in Adams is obtained by modal analysis, which is imported to Adams for establishing suspension model in the end, considering bushing preload to make sure the model more close to real vehicle state. The suspension stiffness and roll stiffness are validated using finite element analysis and experimental data. Suspension kinematics and compliance characteristics and its influence on handling and stability are analyzed in the case of model precision is proved reliable, and compared its K&C characteristics with the benchmark car's, to analyse suspension performance of the R&D model is reasonable or not. Raise a solution for the issues existed in model, torsion beam rear suspension bushing mount orientation and stiffness influences on the vehicle handling and stability are researched using virtual prototypes facing structure based on experimental optimization method, which provide the basis and direction for reasonably matching KC characteristics.The research indicate the rigid-flexible coupling model used in this paper has a high precision for simulation of suspension, which lay the foundation for suspension K&C analysis, and has far-ranging applicability, moreover, using rigid-flexible coupling model make modeling more quick and efficient. The study also shows the rear suspension lateral force toe characteristic has significant influence on vehicle steering characteristics. There is oversteer trend usually under lateral force for the torsion beam rear suspension, Lateral force toe characteristic should be designed to be a positive or weak negative characteristics as much as possible in design, that is in favor of understeer characteristic. The obtained optimization results show lateral force toe characteristic has been remarkably improved; degree of understeer of vehicle has been significantly increased. The optimization method can be used to quickly find the sensitive factors affected on performance, and the factors of attention are optimized, optimal results significantly, providing matching the performance for automotive chassis and suspension optimization with a reference.