Study On The Contradictory Mechanism Of Tire Grip And Rolling Resistance And The Method Of Synergetic Promotion

Rolling resistance and grip is an important performance of tire,rolling resistance affects the fuel consumption of the car.The grip performance of the tire determines the adhesion capacity of the tire,and thus has a decisive impact on the vehicle's steering and braking performance.Tire grip and rolling resistance has a certain contradictory relationship,one performance upgrade,another decline.In the face of increasingly stringent regulatory requirements,it is of great theoretical and engineering application to study the contradictory mechanism of grip performance and rolling performance,and the structural design method of synergistically lifting the both performances.In this paper,295/80R22.5 steel radial truck tire is used as the research object.The rubber friction was tested under different conditions.The tire model was established by using the finite element software and the method of calculating grip force and rolling resistance was elaborated.On this basis,the distribution characteristics of tread three-dimensional deformation are analyzed.The distribution of tread radial deformation is radiated outward from the center.The deformation decreases gradually from the center area to the edge,and the front and rear are symmetrical.In the case of braking,the tread longitudinal deformation of the leading edge of the grounding area is the largest,and the longitudinal deformation in the front is symmetric to the end.In the case of free rolling,the longitudinal deformation of the tread is symmetrical about the center line of the tread,and the deformation in the front is symmetric to the end.Based on the characteristics of the deformation in the grounding area and the distribution of the grounding pressure,the grounding area is divided into 9 parts,which is from A to I,and the tread stiffness matrix is obtained.The tread micro-radial stiffness distribution is gentler in the center of grounded area,no obvious bulge;the extreme value appeared on both sides of shoulder.Tread micro-longitudinal stiffnessdistribution characteristics shows that the radial micro-stiffness at the shoulder was significantly lower compared with the middle area.The relationship between the running velocity,the load,the tire pressure and the side-slip angle on the tread stiffness distribution is studied.The relationship between the grip force,the rolling resistance and the stiffness of the tread surface is established by the multiple regression analysis method.The microscopic distribution of the tread stiffness matrix reveals the contradictory mechanism of the tire rolling resistance and the grip.For some specific areas of the stiffness,regardless of increasing or decreasing the stiffness,it will result in a performance improvement whereas another performance decline.It is precisely because of this contradiction,resulting in rolling resistance and grip performance of the conflict.Through the method of changing the tread height and changing the tread material parameters,different elastic modulus and pattern height are set for different tread regions,the differentiated model is established.Compared to the original scenarios,the grip force of scenarios 2 increased by 20.7N,rolling resistance decreased by5.322N;the grip force of scenarios 4 increased by 28.8N,rolling resistance decreased by 8.24 N.The grip performance and the rolling performance of the tires are synergistically enhanced.