Research On The Effect Of Rubber Aging On Tire Rolling Resistance

The rolling resistance performance of tires directly affects the fuel economy of vehicles.Reducing the rolling resistance of tires can effectively decrease the exhaust emissions of automobiles,saving fuel and reducing environmental pollution.However,the tire rubber material is susceptible to aging due to the external environment（light,heat,etc.）,that is,thermal oxidative aging,which directly affects the mechanical properties of the rubber,and then affects the rolling resistance of the tire.Therefore,studying the influence of rubber aging on rubber mechanical properties and tire rolling resistance has very important theoretical significance and engineering application value.In order to study the effect of thermal oxidative aging on tire performance,four12R22.5 radial truck tires of the same specification were used as the research object.The tire oven aging test at 65°C was carried out in Suzhou Smith Laboratory,and the aging test was performed before and after the aging test.The tire rolling resistance was tested.The results show that with the aging of the tire,the rolling resistance and the rolling resistance coefficient of the tire have decreased.In order to accurately describe the aging degree of the rubber in the tire,the air permeability parameters and oxygen consumption rate of each component rubber of the tire are tested at 65°C,and the aging degree of the tire rubber is indirectly judged by the size of the rubber oxygen consumption.Using the finite element analysis method,the gas diffusion and thermal oxygen aging model of the tire of this specification was established,combined with the Smith oven aging test conditions,the oxygen consumption of the test tire during the oven aging test was simulated and calculated.The results show that the amount of oxygen consumed by different parts of the tire is different.The tread rubber consumes more oxygen during the tire oven aging experiment,while the inner liner rubber consumes the least amount of oxygen.According to the rubber formula of different parts of the tire,six kinds of dumbbell-shaped samples of rubber,including tread rubber,inner liner rubber,and sidewall rubber were produced.The simulation method determined that different rubber samples reached the same level in the oven aging test.The experimental conditions required for the degree of aging,and the aging test was carried out on rubber dumbbell-shaped specimens.At the same time,material parameter tests such as tensile test and loss factor test were carried out on dumbbell-shaped samples before and after rubber aging.Through the analysis of the stress and strain data in the tensile test before and after rubber aging,the results show that the tensile strength of the rubber sample is significantly reduced after aging,and its elongation decreases by 50% or more.Rubber aging will cause its mechanical properties to decrease.In order to effectively calculate the rolling resistance and temperature field of the tire,the specific heat capacity,thermal diffusivity and thermal conductivity of the rubber of each component of the tire were tested.The finite element model of tire rolling resistance and coupled temperature field simulation was established by using ABAQUS software.The simulation analysis of rolling resistance and coupled temperature field of tires before and after the oven aging test was carried out.The results showed that the mechanical properties of the rubber material after the aging of the rubber decrease will affect its tensile strength,elongation at break,loss factor and other material parameters,which will bring about the impact of rolling resistance.The rolling resistance of tires has been reduced by an average of 7% compared with the rubber before aging.