Tread rubber compound effect in winter tires: An experimental study

Abstract

This paper presents an indoor experimental study focused on analyzing the effect of various tread rubber compounds on the tire performance on ice.A set of sixteen tires (two per rubber compound) with identical dimensions, construction, and tread pattern, but of different tread rubber compounds, was investigated using the Terramechanics Rig which measures all forces and moments acting on a tire that is rolling (free or with slip) on ice. All operational parameters (normal load, inflation pressure, ice static coefficient of friction, ice temperature) were kept constant. Testing the tires under free rolling provided insights into the effect of the tread rubber compound on the resistive forces.The investigation led to conclusive evidence that the tread rubber compound affects drawbar pull coefficient significantly (double for best than for the worst tire). It was found that the effect of the tread rubber compound in the lower slip region is most prominent, which is also where vehicles operate most of the time. The decrease in the stiffness is generally considered a positive sign for improvement in available friction but this cannot be a generalized conclusion when analyzing the tire as a whole, which is one of the major findings of this study.