SHOE-SURFACE TRACTION OF CONVENTIONAL AND IN-FILLED SYNTHETIC TURF FOOTBALL SURFACES

Abstract

Both “friction” and “traction” describe the dissipative force that resists relative motion between two surfaces in sliding contact. The classical Amontons-Coulomb laws of friction (Amontons, 1699; Coulomb, 1781) offer a paradigm in which the resistance to relative motion is determined by the coefficient of friction, μ . Modern adaptations of the classical friction paradigm distinguish between “static” friction, the resistance at the instant of impending motion and “dynamic” friction, the resistance during relative sliding motion at constant velocity. In the traditional paradigm, coefficients of friction are material-dependant constants that are independent of time, velocity and contact pressure and the coefficient of static friction, μs, is always greater than the dynamic coefficient, μk.