FE-based Tire Forces And Moments Predictive Method

Tire forces and moments generated in the tire contact patch are reasons for drive, brake and cornering of vehicles. It's important to figure out the generation mechanism of tire forces and moments and ways to calculate them.This paper aims to improve the drawbacks of traditional tire models and build up a predictive tire model which can explain the generation mechanism and calculate tire forces and moments directly from tire structure. The paper has two innovative points: Firstly, a FE based structural method to calculate velocity field has been developed. Secondly, the Mixed Lagrange-Euler method to calculate the contact deformation and forces has been presented.By treating wheel position angles as Euler angles, the rolling tire kinematical expression has been derived under rotation configuration. Based on tire contact kinematics and material velocity constant principle, the deformation and forces can be obtained by integration under translation configuration. It can be degenerated to Fiala model under certain conditions and successfully explain tire ply-steer and conicity. Then the MLE method has been applied to analyze specific tire F&M characteristics along with experiments and effects of different parameters like tread stiffness, friction coefficient and belt structures have been studied.Results show that the cornering and aligning stiffness are controlled by tire structure stiffness, peak lateral force and aligning moment are controlled by friction coefficient. The belt structure determines the belt slip angle, thus affects the effective slip angle and the overall tire F&M characteristics. The maximum error of cornering stiffness is 6.7%, which is satisfactory.The tire F&M predictive method presented in this paper opens up a way to predict the tire external characteristics by directly from tire designs and laid a foundation for future researches on vehicle dynamics.