| Compared with the traditional vehicle matching,virtual matching has many advantages,including greatly reducing the development cost,shortening the development period and improving the matching effect.It has a broad application prospect in vehicle development.The matching of tires and vehicles covers many aspects such as handling stability,ride comfort,braking,economy,and wear.Handling stability,known as the ’ lifeline of high-speed vehicles ’,is the performance that virtual matching needs to focus on.The steady-state cornering characteristics of tires have a crucial impact on vehicle handling stability.Therefore,it is of great significance to study the steady-state sideslip model for virtual matching to promote the development of virtual matching technology.The existing tire steady-state cornering models are mainly divided into theoretical models,empirical models and semiempirical models according to the modeling mechanism.However,they all have their own shortcomings and cannot be directly used for virtual matching of tires and vehicles.Therefore,it is urgent to establish a new steady-state side-slip model with high calculation accuracy,strong prediction ability and suitable for tire design adjustment to meet the requirements of virtual matching.In this paper,based on the research project "Research on Key Technologies in Tire Chassis Matching Process" commissioned by the Gi Ti Tire R&D Center and the common technology project "Collaborative Innovation Research on High Precision Application of Tire Models" of the Tire Dynamics Collaborative Innovation Alliance,the following aspects of research have been carried out around the research issue of tire steady state side-slip models for virtual matching:(1)A high-precision tire finite element model for virtual matching and steady-state cornering characteristics research was established.Firstly,a high-precision finite element model of 205/60R16 92 V radial tire was established through detailed modeling of the tire’s internal structure,tread patterns,rubber materials,skeleton materials,and road friction characteristics;Then,the explicit simulation of the side-slip characteristics is performed using this model;After that,the reliability of the steady state side-slip simulation results is verified by a tire force and moment testing machine;Finally,the effects of belt angle and width,cap structure,carcass structure,height of bead filler and tread rubber on the steadystate cornering characteristics of the tire were analyzed systematically by the finite element simulation.(2)An improved cornering stiffness model based on the flexible deformation characteristics of the beam carcass is established.Firstly,based on the beam theory based on elasticity,the lateral deformation of the carcass subjected to a concentrated force and a concentrated couple is derived;Then,the reliability of the beam model was verified using a finite element model,and the effect of load on the bending and torsional deformation of the carcass was studied;After that,an improved cornering stiffness model based on the beam model was derived,and the effects of tire inflation pressure and vertical deflection on the carcass flexibility characteristic ratio,tread stiffness,carcass torsional stiffness,and carcass bending stiffness were studied through tire footprint and small side-slip tests;Finally,the advantages of the cornering stiffness model proposed in this paper compared to other similar models in terms of modeling mechanism and computational accuracy are analyzed.(3)A steady-state side-slip model considering the characteristics of two-dimensional tire footprint under cornering conditions is established.Firstly,the finite element model was used to analyze the characteristics of the footprint shape and contact pressure distribution after tire cornering,and the relationship model between the contact width,contact length,and contact pressure distribution with respect to lateral force was established;Then,the distribution of lateral stress along the width direction of the tire is analyzed by finite element method,and an ideal model of tread lateral deformation distribution is proposed based on the analysis results;After that,combined with the improved cornering stiffness model based on the flexible deformation characteristics of the beam carcass,a steady-state side-slip model considering the characteristics of the two-dimensional tire footprint under the cornering condition was derived,and the reliability of the model was verified by finite element simulation;Finally,the effects of friction coefficient,rolling speed,contact length,lateral tread stiffness,carcass torsional stiffness,impact factors of contact width and footprint shape on steady-state cornering characteristics of tires were studied through the proposed side-slip model.(4)The proposed steady-state side-slip model is applied to study the influence mechanism of tire design parameters on cornering characteristics.Firstly,based on the steady-state side-slip characteristic data obtained by finite element simulation under different commonly used tuning parameters such as belt angle and width,cap ply and carcass structure,height of bead filler,and tread rubber,the parameters of the steady-state side-slip model established in this paper are identified,and the impact of various design parameters on the intermediate parameters of the model,such as lateral friction coefficient,contact length,carcarss torsional stiffness,is analyzed;After that,the single factor sensitivity analysis method was used to systematically analyze the influence mechanism of various commonly used tunning parameters on tire cornering characteristics such as cornering stiffness and aligning stiffness.The analysis results can be used to guide the design and optimization of tires.(5)The proposed steady-state side-slip model is applied to predict the impact of tire inflation pressure on steady-state cornering characteristics,and a prediction model based on vertical deflection control method was established.Firstly,the influence of inflation pressure on lateral force,aligning moment,and parameters of the proposed steady-state side-slip model under the vertical load control method is analyzed through finite element simulation;Then,aiming at the problem that the influence mechanism of tire pressure on cornering characteristics is complex and difficult to predict,a steady-state side-slip model based on deflection control method is proposed;After that,the variation characteristics of cornering model parameters with inflation pressure is studied when the vertical deflection is fixed,and the corresponding prediction model is established.Finally,the reliability of the model is verified by finite element simulation.Through the above series of studies,the following conclusions can be obtained:(1)The beam carcass model can well express the flexible deformation of the carcass when the tire is subjected to lateral force and aligning moment.After incorporating the carcass deformation caused by aligning moment derived from the beam carcass model into the small sideslip analysis,the fitting accuracy of the cornering stiffness and aligning stiffness can be significantly improved.At the same time,it is found that the values of the bending characteristic ratio and the torsion characteristic ratio of the carcass are equal.(2)The shape,width and normal pressure distribution of the contact patch after tire cornering are significantly affected by the value of lateral force.The calculation accuracy of the steadystate side-slip model can be significantly improved by incorporating the influence of lateral force on the tire footprint into the calculation of lateral force and self-aligning torque.(3)The new steady-state side-slip model proposed in this paper can effectively reveal the influence mechanism of tire design parameters such as belt angle,cap structure and tread rubber modulus on cornering characteristics.(4)The vertical loading mode of the tire is changed from load control to deflection control,which can decouple the influence of inflation pressure on the tire footprint and the carcass stiffness,and make the law of friction coefficient,torsional stiffness of carcass,cornering stiffness and aligning stiffness changing with inflation pressure simple and easy to predict.The prediction model of the influence of inflation pressure on steady-state cornering characteristics based on deflection control proposed in this paper only needs the data of cornering under two inflation pressure conditions to predict the steady-state cornering characteristics within a large range of inflation pressure changes.Whether it is interpolation prediction or extension prediction,it has high prediction accuracy,which is better than the Magic Formula model. |
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