The Effect Of Unsprung Mass On Vehicle Performance

At present, simplified vehicle model was widespread used in the research aroundvehicle unsprung mass, because of the ignorance of suspensions’ detailed parameter, theauthenticity of the simulation was influenced. In order to analyze how the suspensions’detailed parameter improve the vehicle dynamic performance influenced by unsprung mass,the article builds a nonlinear system model of double wishbone suspensions, by whichanalyzes the vehicle dynamic performance. It turned out that adjustment of the suspensions’detailed parameter could improve the vehicle dynamic performance influenced by unsprungmass.Firstly, based on relevant assumptions, the article simplified the vehicle vibration model,and built tridimensional simplified vehicle model and planar double-shaft simplified vehiclemodel; setting the partition coefficient of suspensions weight, built quarter simplified vehiclemodel; using correlation theory of unsprung mass, the article also redefined the quartersimplified vehicle model, and rebuilt a improved one that was compliant in this research.Secondly, the article build physical model of double wishbone suspensions. Based onthe physical model, the study got a nonlinear system model of double wishbone suspensionsby means of kinematical and kinetic equation derivation. The article also verified the modelwas accurate.Finally, based on the matlab software, the study compute the nonlinear model achieved.Using different ratios of unspung mass, the article also analyzed the influence of unsprungmass for vehicle dynamic performance, such as vehicle smoothness, handling stability andsuspension design limit. Adjustment and analysis of suspensions’ detailed parameter, the study confirmed basis of suspension design and adjustment.