Study On Tire Grounding Mechanical Characteristics And Its Application In Vehicle Handling Stability

Tires as a vehicle the only parts contact with the ground,play an important role in the running of the vehicle,inherit from pavement longitudinal,transverse and vertical reaction force.The basis of the dynamics of tire ground mechanics vehicle dynamics research,vehicle operation stability,smoothness,dynamic,braking,etc.are affected by the contact characteristics of the tire/channel.Rubber-cord composites consisting of tire structure,lead to tire nonlinear changes in loading process.To improve vehicle handling stability must first ensure the tires in the process of turning,braking and driving is not abnormal.In this paper,refer to a large number of literatures on the mechanical characteristics of tire grounding and its influence on handling stability are consulted,and the research status is comprehensively analyzed.Combined with bench test and simulation of tire mechanical characteristics and real vehicle test and simulation of vehicle handling stability,the mechanical characteristics of tire grounding and its application in vehicle handling stability are studied.Firstly,the finite element analysis and simulation model of tire grounding mechanical characteristics and PAC2002 tire dynamics model are established.Using the tensile testing machine for 10 kinds of glue and two main types of tire and rubber cord tensile test,the rubber cord composite cord extraction experiments,the Yeoh model is used to characterize the mechanical properties of rubber materials,and the Rebar element is selected to simulate the rubber-cord composite materials.A more accurate tire finite element model is established in Abaqus by using the obtained model parameters.On the basis of PAC2002 tire model,combined with the calculation method of main tire parameters which have great influence on handling stability,the parameters are identified,and the mathematical models of tire input parameters and output parameters under different test conditions are derived.The relationship between lateral force-slip angle,aligning moment-slip angle,lateral force-slip angle,aligning moment-slip angle and longitudinal force-slip ratio is compared and verified by using test data.Then,the tire tests were carried out under different test conditions,including longitudinal sliding,cornering,rolling and compound conditions.The machine learning module of Python was used to identify and train important test parameters,and the functional relationship between longitudinal force peak value and speed and roll angle under longitudinal sliding stiffness and positive and negative slip rate,the functional relationship between cornering stiffness,lateral force peak value,righting stiffness and righting moment peak value and speed and load under steady and transient conditions were obtained.Evaluation of indicators through parameter identification,it is found that the tire parameter identification is effective,and the relationship between important parameters and variables can be accurately expressed.After combined with the experiment and simulation analysis of the structure of the tire parameters and use docking the influence of the mechanical properties.Select the five most important rubber and skeleton structure parameters of tire,such as carcass ply number,diameter of belt steel wire,angle of belt steel wire,height of triangle rubber and hardness of tread rubber,were selected,and the influence of these parameters on the mechanical characteristics of tire grounding was analyzed.Research grounding printed evaluation parameters(grounding area,grounding coefficient,average grounding pressure,rectangular rate and hardness coefficient),longitudinal slip evaluation parameters(longitudinal force and slip rate relationship,longitudinal force peak and longitudinal rigidity and load relationship),The evaluation indicators of the tire structural parameters of the tire structure parameter(relationship between lateral offset evaluation parameters(relationship between lateral force peak and side flanging stiffness and load),the evaluation parameter(returning torque peak and the relationship between returning rigidity and load).Using ABAQUS simulation experiment,the influence of service parameters such as load,tire pressure,friction coefficient between tire and road surface and speed on grounding characteristics is analyzed.The force law of tire belt cord which can not be accurately obtained in the test is explored,which provides a basis for tire structure design.Finally,has carried on the three different tire structure and material properties of the vehicle steering stability field contrast test and simulation,including steady-state rotation test and steering wheel angle step test,the obtained parameters such as unstable vehicle speed,yaw rate response time and lateral acceleration response time show that the simulation and test results fit well and the modeling method is accurate.Based on the tire six-component force test data of three test speeds of 40km/h,60km/h and 80km/h and two test methods of steady state and transient state,establishment of six tire models by orthogonal combination,and the whole vehicle is imported for simulation of double lane shifting,steady state rotation,steering wheel angle step,steering wheel angle pulse and steering wheel sine input.It is found that there are some differences among different tire models in handling stability simulation,and its influence law is analyzed.