Volume 41, Issue 5 (September 1996)
The Effect of Contact Pressure and Test-Foot Sliding on Slip Resistance: Experimental Results
Since the inception of interest in friction, the effect, if any, of contact pressure has been investigated. DaVinci, Amontons, and Coulomb, three early investigators, found no effect. The development of interest in walkway safety tribometry, the measurement of friction at the shoe-bottom/walking-surface interface, suggests a reassessment of the applicability of Amontons-Coulomb because the shoe bottom is resilient and because the interface between the shoe bottom and the walkway surface is frequently contaminated, for example, with a liquid such as water. In any such reassessment, the relationship between contact pressure and the friction coefficient becomes worthy of attention. Contact pressures in normal walking can vary upwards from a few psi to over a thousand psi (heelstrike in high-heeled shoes).
This paper will explore the historical background and experimental research in the literature and present the results of our experiments which explore the relationships between contact pressure and friction. The effect on friction of test-foot sliding is experimentally analyzed.
The relationship between the tribological results presented here and real-world walkway safety are discussed. The effect of test-foot polishing is analyzed. Future areas of investigation are discussed.