Finite Element Analysis of elastomer: Case study – Rolling resistances of pneumatic and solid tyres

Abstract

EU tyre labelling rules have been applied since November 1st, 2012, to inform about the performances of tyres on fuel efficiency (rolling resistance), safety (braking on wet surfaces) and noise (external noise). The tyre labels help customers to make their purchase decisions by trade off on tyre performances and prices. Consequently, manufacturers have to engineer their products so that their tyres are classified on top of the label categories. Tyre rolling resistance involves in many kinds of tyre knowledge such as rubber formulations, tyre structures and tyre tread patterns. Generally, 70% of tyre rolling resistance depends on the hysteresis properties of rubber compounds and 30% depends on other properties such as road conditions, tyre pressures, load carrying, vehicle speeds, and tyre tread designs. From this point of view, even if rubber compounds are formulated to have good hysteresis properties, they can help reduce tyre rolling resistance up to 70%. If tyre rolling resistance needs to be further reduced, tread designs have to be considered. Therefore, this case study will show how to reduce tyre rolling resistance by using Finite Element Analysis (FEA). Pneumatic light truck tyres were used to study their tread patterns, tread depths and contact areas affecting their rolling resistances, while solid tyres were used to study on their tread patterns, tread depths, contact areas and tyre structures affecting their rolling resistances. The FEA results showed that tread patterns had high effects on rolling resistance of pneumatic light truck tyres while they had little effects on solid tyres. Contact areas and tread depths affected rolling resistances of both tyres. Increase in contact areas reduced tyre rolling resistances while increase in tread depths resulted in higher tyre rolling resistances.