Factors Influencing the Measurement of Slipperiness

Abstract

The evaluation and prevention of slips and falls require methods of quantifying the slipperiness of floors. The concept of coefficient of friction (COF) has been and continues to be commonly used as one such method. The objective of this paper is to present some results from investigations into the effects of vertical force and velocity on COF measures for different types of floors. Tests involving both static COF (SCOF) and dynamic COF (DCOF) measurements were performed under various conditions. It was found that the SCOF changed as a function of the vertical force used. Generally, the SCOF increased as the vertical force was increased. This was not true, however, for tile floors. It was also found that there was a significant first order interaction effect on the SCOF between vertical weight and the condition of the floor (wet or dry). The dynamic tests showed that velocity of the shoe material with respect to the floor had a large effect on the DCOF values obtained. The velocity effect was dependent on the shoe material and the conditions tested. Possible reasons for these findings and ramifications on slip testing are presented.