Research On The Contradictory Mechanism And The Collaborative Improvement Method Of Tire Rolling Resistance And Grip Performance

The tire labeling laws issued by EU,as well as the "green tire technical specifications" issued by China,all put forward higher and more comprehensive requirements for tire rolling resistance,grip and other performance,but there are different degrees of incompatibility between these performances.Therefore,the development of green tire technology must break through the problem of incompatibility between its performances.In this paper,ten 205/55R16 radial tires with different tread patterns were selected as the research object.In order to obtain the static grounding characteristics of the tire,on the one hand,the geometric characteristics and pressure distribution of the tire in contact area were obtained by Tekscan pressure test system;on the other hand,the distribution of tread deformation in contact area of tire under vertical load was measured by VIC-3D non-contact full field strain measurement system.By subdividing the contact area and defining the characteristic parameters to describe the contact state of each area,a parametric evaluation system to express the geometric and mechanical information of tread in contact area was constructed.Using correlation analysis method to select the grounding parameters which are significantly related to the tire rolling resistance and grip performance,and the influence of the grounding characteristics on the tire rolling resistance and grip performance was analyzed.Then the contradiction mechanism between tire rolling resistance and grip performance was explained,which is reflected in that to improve the grip performance of the tire,it is necessary to reduce the transverse tensile strain of the tread in contact area and increase the longitudinal tensile strain of the tread,but with the increase of the longitudinal tensile strain,the rolling resistance of the tire will also increase,which leads to the contradiction between tire rolling resistance and grip performance.The partial least square regression method was used to predict the rolling resistance coefficient and braking distance of tire,and an evaluation method of tire rolling resistance and grip performance based on the grounding parameters was proposed.In order to simplify the regression model,the significance test of the regression coefficient was carried out by bootstrap resampling method to screen out the ground characteristic parameters which have significant explanation effect on the performance,and the tread functional areas that have a significant impact on the tire performance were identified.A finite element model of 205/55R16 tire with complex tread pattern was established.The validity of the finite element model was verified by static ground imprint test and tire stiffness test.Based on the influence of the grounding characteristics on tire rolling resistance and grip performance to guide the tread modification design,and the universality of the evaluation method based on the grounding parameters was verified.The concept of regional design of tread was put forward and the optimization scheme was designed.Compared with the original scheme,the rolling resistance of the optimization scheme is reduced by 2.633 N,and the grip force is increased by 6.428 N.In view of the contradiction between rolling resistance and grip performance,the influence of the number and width of lateral grooves in outer shoulder area on tire rolling resistance and grip performance was analyzed.A concave transverse groove structure with narrow groove in the middle and wide groove at both ends was proposed in the outer shoulder area.Compared with the original scheme,the rolling resistance of the optimization scheme is reduced by 2.112 N,and the grip force is increased by 10.196 N,realizing the cooperative improvement of tire rolling resistance and grip performance.