Characterization of Cut and Chip Damage in Ultra Low Rolling Resistance Tire for Electric Vehicles

Since the inception of battery driven electric vehicles in the automotive world, there has been a constant challenge in maximizing the range of an electric vehicles through various means including battery technology, vehicle weight optimization, low drag coefficients etc. The tires being a viscoelastic composite material have now become a vital to the range performance of an EV. The rolling resistance of a tire is now become a hotter topic than ever. The rolling resistance coefficient (RRC) is the measure of energy loss during rolling due to viscoelastic dissipation in the tire. The viscous dissipation in tire arises due to hysteresis in the various components of a tire including tread, sidewall, inner liner, apex etc rubber compounds. The internal friction between layers of body ply, steel belts and tread crown ply also contribute to the internal heat generation. Therefore, the development of ultra-low RRC tires is a serious challenge for tire engineers. Nevertheless, the recent advances in the tire technology, which include introduction of new generation reinforcing fillers in rubber compounds, tread pattern design and construction matrix optimization, allow the tire experts to carefully select the suitable material and design parameters to meet the performance characteristics and durability of an EV tire. This paper demonstrates the scientific way of analysing cut and chip failure in tires which is one of the most frequent and troublesome challenge in the development cycle of low RRC tires. The various material characterization techniques which include viscoelastic behaviour of tread rubber compound, polymer-filler interaction and filler dispersion in tread rubber compound were studied along with the tire footprint characteristics. Eventually a better comprehensive understanding was drawn on the impact of material behaviour and tire characteristics on the cut and chip damage of ultra-low RRC tires for EV vehicles. Keywords: Electric vehicle, Tire Technology, Rolling Resistance Coefficient (RRC), Cut and Chip, material characterization, Tire testing