Tire tread block dynamics

Temperature has a crucial influence on rubber friction and tire dynamics.The temperature field in a rubber tread block is the sum of the {\it background temperature}$T_0({\bf x},t)$, which varies slowly in time and space, and the {\it flash temperature}$\Delta T({\bf x},t)$, which in nonzero only close to themacroasperity contact regions, and which varies rapidly in time often on the millisecond time scale.Here we study the motion of a single tire tread block and how it is influencedby the flash temperature. We also present a theory and experimental results forthe size of the macroasperity contact regions.In particular, we show that for a large enough nominal contact area,in most cases the diameter $D$ of the macroasperity contact regions are nearly independentof the elastic modulus and the nominal contact pressure.