Research On Flexible Ring Model Applied To Short Wavelength Uneven Road

Mechanical performance of Tires is completely different under different excitation,so different tire model is suitable for different conditions.The tire model suitable for analyzing the low-frequency mechanical properties of tires has become more and more perfect after continuous research by domestic and foreign scholars.However,there are relatively few studies on the tire models for high-frequency dynamic tire analysis in Domestic research.The domestic research on the tire model suitable for the analysis of the high frequency mechanical characteristics of tires mainly focuses on the rigid ring model and does not fully consider the deformation of the tire belt.When the belt is deformed by the short wavelength unevenness at high speed,the rigid ring model is not accurate enough to express the mechanics of the tire.Therefore,In this paper,the discrete element method is used to discriminate the tire belt part into multiple mass points connected by springs.The sidewall part is discretized into spring damping,and a kind of tire flexible loop model with deformable belt is established and uses the established tire flexible ring model to simulate static stiffness,ground imprint simulation and over-cleat dynamic simulation.Finally,the simulation results are compared with the experimental data to get a more accurate tire flexible ring model.The first chapter is the introduction,which mainly introduces the research status of the tire flexible ring model suitable for the analysis of the mechanical characteristics of high-frequency tires at home and abroad,And some calculation methods of contact force between tire and road surface are introduced: brush model,magic formula model,Uni Tire model and numerical simulation method.Finally,the research contents of the full text are briefly introduced.In order to study the mechanics characteristics of tire,the second chapter introduces tire ground mark test,vertical stiffness test,longitudinal stiffness test and tire cleat test.The experimental procedures and test methods for these experiments are introduced.It provides the experimental basis for the parameter determination and model verification of the tire flexible ring model.The third chapter builds a two-dimensional tire flexible ring model based on discrete element modeling.In this model,the belt is dispersed into a plurality of belt mass points,and adjacent belt mass points are connected by springs.A plurality of contactless mass-contact units are evenly distributed between adjacent belt mass points.Belt mass point and the rim through the spring damping connection to simulate the elasticity of sidewall and inflation pressure;The model calculates the contact force between the tire and the road surface based on the penalty function method and the coulomb friction method,and considers the stick-slip characteristics of the tire.Finally,the Lagrange principle is used to derive the kinetic equations of rim and mass points to establish the tire flexible ring model.The fourth chapter introduces the relationship between the model simulation results and the parameters in the model and provides guidance for the determination of the model parameters.And a series of simulation analyzes are conducted with the good fitting parameters,and compared with the corresponding experimental data in Chapter 2,the model accuracy is verified.The fifth chapter is the summary and prospect of the full text.