Study On Dynamic Friction Property Of Tire And Its Effect On Vehicle Handling

In this paper, a test system of tire tread rubber friction was first established and test datawas obtained with it. Then theoretical research on tire slip was done and a series of tiremodels considering dynamic friction of rubber were provided, such as, Unified Brush TireModel considering Simplified Dynamic Friction (UBTMSDF), Unified Theoretical TireModel considering Dynamic Friction(UTTMDF), Unified Exponential Semi-Empirical TireModel considering Dynamic Friction(UESETMDF). To evaluate the influence of tire rubberdynamic friction on vehicle handling performance, the UESETMDF tire model was selectedto do vehicle dynamic simulation. The specific procedure is as below. To understand deeply on rubber friction property, friction experiments of tire treadrubber unit on dry concrete road surface and icy road surface were conducted. Tire rubberfriction test data at different slip velocity, vertical pressure, ambient temperature was obtainedwith an efficient test method on the friction test system. When fitting the friction test data,Savkoor model was selected. To express all the test data at different condition globally,vertical pressure and ambient temperature factor were added into Savkoor model as anothertwo independent variables besides slip velocity. Friction parameters were obtained by fittingthe test data and understanding on rubber dynamic friction was deepened. Theoretical work was carried out after friction experiments. Based on the current UnifiedBrush Tire Model, a tire model considering simplified dynamic friction (Stiction) was firstbuilt. By changing the kinetic friction coefficient μd and static friction coefficient μs ofthe Stiction model, the influence of dynamic friction was briefly evaluated. Combining withIV英 文 摘 要the rubber friction test data obtained previously, different group of μd and μs was set tobe equally regarded as tire dynamic friction coefficient at different rolling speed respectively.For example, at low speed, the friction coefficient increases with slip velocity, so μd shouldbe larger than μs . With the variation of μd and μs , F&M property in the Unified BrushTire Model was calculated and the influence of rolling speed was evaluated to some extent.Although the friction model added into the tire model was simplified, its results found a goodbase for the development of tire semi-empirical model. The Unified Tire Brush Model used in previous chapter only considers the stiffness oftread while omitting the stiffness of carcass. To calculate the tire force more precisely, thestiffness of carcass was considered in the Unified Theoretical Tire Model. Based on thismodel, and provided with tire rubber friction model obtained, study on the influence ofdynamic friction on tire F&M property was carried out on more thorough level. The UnifiedTheoretical Tire Model considering Dynamic Friction was established. The influence of slipvelocity, vertical pressure, and ambient temperature on tire sideslip property was estimated bycalculating the F&M with the model. In this chapter, a unique method of combining the tirerubber unit friction test and tire theoretical calculation. And this could be a substitute of thosehigh cost, complex and dangerous tire test at different rolling speed, road surface, etc. Withmore factors considered in the chapter, the understanding on tire dynamic friction wasdeepened to a higher level. The influence of dynamic friction to tire sideslip property is obvious from the abovework. However, the shortcoming of theoretical tire model limits its application to industryfield. To solve this problem, Unified Exponential Semi-Empirical Tire Model consideringDynamic Friction (UESETMDF) was established. The coefficient of the model wasdetermined according the boundary condition from the 'UBTMSDF' model. A series of tiresideslip test data was fit with 'UESETMDF' model. And the fitting accuracy of the model wascompared with the model that did not consider...