Research On Tire Thermal Model Considering Tread Friction And Rubber Viscoelastic Properties

The tire is the only part of the car that is in contact with the road surface.The contact characteristics between the tire and the road surface determine or indirectly determine the braking,acceleration and steering characteristics of the car.Therefore,it is of great significance to study the tire dynamics and the friction characteristics between the tire and the road surface.The material composition of the tire is very complex,and it is a typical viscoelastic structure.The tire will undergo various deformations during the movement.Due to the viscoelastic properties of the rubber material,all parts of the tire will generate heat.The temperature of each part of the tire is different,which leads to heat transfer.The most noteworthy is the temperature of the tread,it affects the friction characteristics between the tire and the road surface.When the car is in the process of braking or accelerating,the friction between the tire and the road will cause the temperature of the tread to rise rapidly,thus affecting the dynamic characteristics of the car.When the tread temperature reaches a certain value,the increase in temperature will lead to the reduction of tire adhesion,which will affect the safety of the car during driving.Therefore,it is necessary to establish a tire thermal model considering tread friction and rubber viscoelastic properties.The research on tire thermal model is mostly based on finite element model.Although it can express the temperature distribution of each part of the tire in detail,it is computationally intensive and timeconsuming,and requires some complicated experiments to obtain various parameters of the tire material.Based on the in-plane discrete element model of the tire,this paper introduces the tread rubber material model and establishes the tire model considering the temperature.The main contents are as follows:In the first chapter,several typical tire dynamic models and tire thermodynamic models are introduced,then the research status of viscoelastic material model and friction model are introduced,and finally the research content of this paper is briefly introduced.In the second chapter,the material properties of the tread rubber material is introduced first,and then we use the DMA(Dynamic Mechanical Analysis)test to identify the material parameters of the integer-order material model and the fractional-order material model.The two types of models are compared,and finally we choose the generalized Maxwell model which n=3 as the material model used in this paper.Finally,the relationship between material dynamic characteristics and friction characteristic curves,and the conversion between material parameters and mechanical parameters are introduced.The content of the third chapter is the establishment of tire thermal model.Firstly,the tire rolling resistance experiment and the tire over cleat experiment are introduced,then the heat generation model and heat transfer model are established based on the two-dimensional discrete element tire model,and the tire heat balance equation is established through the Fourier heat conduction equation and the law of energy conservation.Then,the parameter identification of tire dynamic parameters and thermodynamic parameters is carried out through the experimental data.Finally,the rolling resistance and tread temperature of the model were verified.In the fourth chapter,we use the time-temperature superposition principle and the Savkoor friction model considering the contact pressure to establish the friction model considering the temperature,and then uses the tread rubber block friction experiment to identify the relevant parameters of the friction model.The parameters of the tire thermal model were identified by the tread temperature measured in the pure longitudinal slip test,and then combined with the friction model considering the temperature to verify the model,and compared with the simulation results without considering the temperature.The fifth chapter summarizes the full text and looks forward to the future research content.