Experimental Aspects of Friction Research on the Macroscale

摘要: The earliest investigations of sliding friction were prompted by engineering problems like the launching ships and braking wagon wheels. Experiments first performed on objects themselves, later, building replicas that could be more conveniently managed. Concepts for early measuring instruments are credited to Leonardo da Vinci who documented his designs various sleds, pulleys, journals inclined planes during period 1452-1519 [Dowson (1979)]. Recent work has benefited from development sensors capable recording forces with high precision accuracy. Yet, even in face such advances, coefficients still usually reported only one or two significant figures. Additional measures fractional behavior now readily available. These will discussed later.