路面激励下车辆悬架滞回模型的混沌研究

Chaotic behavior of hysteretic suspension model excited by road surface profile

为了分析车辆悬架在实际路面激励下的振动状态,根据试验所得的磁流变减振器示功曲线,采用Matlab软件拟合修正的Bouc-Wen模型,建立带滞回特性的非线性模型以及基于减振器试验数据的两自由度四分之一悬架模型.研究该半主动悬架的频率响应特性,通过相平面图、Poincaré截面图和分叉图分析半主动悬架在不同路面激励下的振动形式,研究随着路面变化或者悬架自身参数变化引起的振动形式的改变,揭示悬架系统在各种工况下发生的混沌行为,为地面车辆的动力学设计提供依据.

The indicator diagram of magneto-rheological fluid damper was collected from experiments in order to analyze the vibration status of vehicle suspension under practical road profile.Then a modified Bouc-Wen model,which was a nonlinear model with hysteretic loop,was conducted by Matlab according to the experimental data.The model of semi-test two degree of freedom a quarter suspension was established.The frequency response characteristics of the model were analyzed,and the nonlinear characteristics were indicated in amplitude-frequency characteristic curves.The vibration form under different road excitation was judged by phase portrait,Poincaré diagram and bifurcate diagram,and the transfer of vibration form was influenced by either pavement excitation,or damping and stiffness of suspension.Results indicate the chaotic behavior under variable situations and provide the basis for the dynamic design of ground vehicle.