Tire Industry 

Abstract: The principle and method of low noise tread patterns design and the assessment criteria of low noise are described.The principle of low noise tread patterns design is as follows:a)the width ratios between different tread blocks and different tread grooves should be irrational;b) the more tread ribs,the lower tread noise;c)the pitch ratios of tread patterns should be irrational;d)the pitch series of tread patterns should not be arranged periodically;e)the tread patterns units should be reasonably misaligned,and the ratio between the deviation and the tread patterns period should not be integral;and the longer tread patterns period,the lower tread noise.The various tread patterns with low noise are designed based on the above said principle,the noises of these tread patterns are simulated by the computer,and the various designs are compared and optimized according to the assessment criteria of low noise to obtain the optimum design.

Abstract: The heat build-up of 10 rubber compounds in a radial tire was investigated.The curves of heat build-up vs temperature or frequency for 10 compounds were respectively obtained by measu-ring the dynamic mechanical properties;and then the dual regression analysis was made to obtain the equations for the dependence of heat build-up of 10 compounds on temperature and frequency.The obtained equations could be used to quantitatively analyze the hysteresis heat source of tire temperature field.

Abstract: The determination of the elastic constants for cord/rubber composite in FEA of tire was investigated based on the micro and macro mechanical theories.The application of Halpin Tsai formula,Gough Tangorra formula and Akaka Hirano formula in the calculation of the elastic constants of cord/rubber composite (longitudinal elastic modulus E 1,lateral elastic modulus E 2,shear modulus in plane G 12 ,primary Poissons ratio μ 12 and second Poissons ratio μ 21 ) which were simplified as a single ply composite of same nature in lateral direction was described.It was proposed that the charge percentage of the cross sectional area of steel cord could be used to chareacterize the Poissons ratio of steel core μ ,and recommended that the fixed cross section method was used to determine μ .The elasticconstants of different cord/rubber composites could be determined by laser spot scatter method,clou ding method and rail shear method.The phenomenon that μ was greater than 1 was discussed.

Abstract: The immune concept was introduced based on the genetic algorithm to propose an immune genetic algorithm,by which the structural parameters of tread patterns were optimized.The defects,such as susceptive degeneration,premature,low speed and monosolution of genetic algorithm,were eliminated by using immune genetic algorithm,at the same time,the convergence during the optimization of tread patterns' noise and the adaptability of optimization improved,the speed and confidence of optimization increased,and the multi-solutions were obtained to provide more choices in design.