The Nonlinear Vibration Character Analysis Of Vehicle Suspension Systems

In the 21^st century,with the development of electro hydraulic control and computer technology,the improvement of manufacturing technology of sensors, electro components and hydraulic control components,as well as the in-depth study of new materials,the performance and control technology of automobile suspension have been constantly improved and its structure has also been improved unceasingly. Because nonlinear factors exist in a wide range of automobile systems,the study and development of automobile suspension and its vibration control system have become a key topic in the vehicle engineering area at home and abroad.Building the nonlinear model of automobile suspension and using the modern nonlinear dynamics theory to study the model,is very important to reveal the vibration rules of automobile suspension.This paper mainly uses the method of average to solve the automobile suspension's nonlinear oscillation differential equations,analyze its vibration characteristics and provide the theoretical basis to the optimal design and reasonable control of the automobile suspension.The main contents include as follows:1,For the variable cross-section spring suspension system,set up the nonlinear automobile suspension model of 1/4 body,establish the movement differential equations for the suspension springs and the nonlinear traits of tire respectively,use the KB method of nonlinear theory to solve the equations and get the approximate analytical solutions.Analyze the numerical and analytical solutions by using the MATLAB,and have discussed the impacts of nonlinear spring stiffness, damping coefficient and ground roughness to the resonance curve.2,For the magnetorheological suspension system when considering the tire's damping coefficient,set up the movement differential equations of the automobile suspension model of 1/4 body.Unfold the magnetorheological variable damping force with Taylor,use the KB method to solve the equations and get the approximate analytical solutions,analyze the solutions with MATLAB and get the impactive curve of nonlinear spring stiffness,damping coefficient and ground roughness to the resonance curve and provide theoretical basis to the optical design and reasonable control of the suspension.