PREDICTION OF ROLLING RESISTANCE FOR TRUCK BUS RADIAL TIRES WITH NANOCOMPOSITE BASED TREAD COMPOUNDS USING FINITE ELEMENT SIMULATION

Abstract

ABSTRACT Tire rolling resistance (RR) is a key performance index in the tire industry that addresses environmental concerns. Reduction of tire rolling resistance is a critical part of lowering fuel consumption, which could be achieved by changing both design and compound formulation. The major challenge is availability of a suitable software code to evaluate RR of tires using nonlinear viscoelastic properties of rubber. We developed a rolling resistance code and used it to predict rolling resistance of truck bus radial tires with nanocomposite based tread compounds. The energy dissipation in the tire is evaluated using the product of elastic strain energy and loss tangent of materials through post-processing using the rolling resistance code developed in this work. The elastic strain energy is obtained through steady state rolling simulation of tires using commercial software. The loss tangent versus strains at two reference temperatures is measured in the laboratory using a dynamic mechanical thermal analyzer. A temperature equation is developed to incorporate the effect of temperature on loss energy. Good correlation of rolling resistance is observed between simulation and experimental results. Nanocomposites used in this study are prepared based on natural rubber and polybutadiene rubber blends with either organoclay and carbon black or organoclay and silica dual filler system. Carboxylated nitrile rubber, a polar rubber, is used as a compatibilizer to facilitate the clay dispersion in the rubber matrix. Compared with general carbon black or silica tread compounds, substantial improvement of rolling resistance is predicted by finite element simulation with nanocomposite based tread compounds containing dual fillers.