РАСЧЕТ ВЯЗКОУПРУГИХ И ТЕРМОМЕХАНИЧЕСКИХ ПАРАМЕТРОВ ШИННЫХ РЕЗИН ПО РЕЗУЛЬТАТАМ ДИНАМИЧЕСКИХ ИСПЫТАНИЙ

Abstract

Viscoelastic and thermomechanical properties of tire rubbers have been studied to predict hysteresis losses during rolling of automobile tires. The temperature dependences of the elasticity modulus and the tangent of mechanical losses obtained by dynamic mechanical analysis and combined tests in the mode of quasi-static cyclic stretching with subsequent relaxation were used for the calculated determination of the deformation and dissipative parameters of 20 rubber compositions. As a basic theoretical description of rubber as a thermorheologically simple material, a linear viscoelastic Prony model is used, for the identification of which the Willams–Landel–Ferry (WLF) temperature-time analogy is used. The advantage of the computational and experimental approach used is the ability to determine the parameters of the WLF equation regardless of the values of other material characteristics. A fairly simple Mooney–Rivlin potential function for an incompressible material is used to describe large elastic deformations of the elastomer under study. The relaxation curve obtained by means of quasi-static tests is applied to assess the adequacy of the constructed mechanical and mathematical model. In particular, the comparison of the experimental relaxation curve with the results of calculations for tread rubber showed a discrepancy not exceeding 15 %. The performed analysis of viscoelastic and thermomechanical parameters of tire rubbers covers (and significantly exceeds in frequencies) the range of operating temperatures and loads of automobile tires. The results obtained can be used in the computational optimization of the composition of materials and the design of automobile tires according to the criterion of rolling resistance and minimizing heat generation in the tire during movement.