Simulation Analysis And Optimization Design Of The Mcpherson Independent Suspension: The Example From A Front Suspension Produeced By Xi’an BYD Automibile Factory

With the huge progress of science and technology, people have more and more dependence on varieties of vehicles, which directly promotes the rapid development of automobile industry. And as the improvement and innovation of vehicle manufacture process, more requirements have been proposed in stability and operating performance of vehicles. The suspension is the component that supports impact load while vehicle traveling, thus affects the operating performance. Therefore, in the view of specific structure of vehicles, the performance of suspension plays an important role in comfortableness and maneuverability of vehicles.This paper takes the McPherson front suspension of a certain type vehicle produced by Xi’an BYD automobile factory as the research objects. Based on dynamics theory of multi-body system, the accurate model of McPherson suspension multi-body system is constructed and simulated in mechanical dynamics software ADAMS. By changing and optimizing alignment parameters, the influence relationship between suspension parameters and driving comfortableness of vehicle is obtained.Through the repeated revision and calculation to optimized objects, the optimum alignment parameters of front wheel are obtained, which provides the reference for improvement of driving stability and reformation of vehicle design as well.The main work is as follows:1. In this paper, the related theory about suspension is briefly introduced, which contains the basic types, functions, and the common research method of vehicle suspension. Meanwhile, the multi-system dynamics theories including the history of the development, main research method, basic principles of establishing model and solving process are presented. Moreover, the using methods of ADAMS / CAR software and procedures of modeling are initially introduced.2. Structural analysis of the McPherson suspension of vehicle produced by Xi’an BYD automobile factory is selected to obtain the parameters information of each part. Next the suspension model and test-bed of virtual prototype are constructed and simulated in ADAMS/CAR software. The curve of wheel alignment parameter is generated utilizing the ADAMS/PostProcessor function. Through analysis to the curve of the wheel alignment parameters, the deficiencies of suspension are identified to get prepared for further optimization of suspension.3. With the Insight module of ADAMS / CAR software the suspension guiding mechanism is designed. And the virtual simulation model is optimized to obtain the factor that influences the wheel alignment parameters greatly. Taking these experimental factors as designed variables to calculate numerically, the optimized design of suspension guiding mechanism is completed. In this way, parameters variation graphs of suspension could operate within reasonable limits, which realize the optimal design of suspension.