Measurement of the coefficient of friction (COF) between the shoe/sole and the floor is essential in understanding the risk of slipping accidents. COF measurements between the footwear material and floor using a slipmeter were commonly performed using flat footwear pads. Such measurements might underestimate the actual slip resistance of people's daily experiences because tread groove design on footwear is very common. This research investigates the effects of the tread groove width on the measured COF. The results indicated that tread groove width significantly (p<0.0001) affect COF under various footwear material, floor, and contamination conditions. Wider tread grooves resulted in higher COF values with a few exceptions especially on oil contaminated floor. Stepwise regression was performed to establish a linear regression model between COF and the tread groove width under footwear material/floor/liquid-contamination conditions. A seven-independent-variable model with an adjusted R^2 of 0.74 was obtained. The lack of fit test result for the model was significant at p<0.0001, indicating that the model adequately fit the friction measurement data.
Measurement of the coefficient of friction (COF) between the shoe/sole and the floor is essential in understanding the risk of slipping accidents. COF measurements between the footwear material and floor using a slipmeter were commonly performed using flat footwear pads. Such measurements might underestimate the actual slip resistance of people's daily experiences because tread groove design on footwear is very common. This research investigates the effects of the tread groove width on the measured COF. The results indicated that tread groove width significantly (p<0.0001) affect COF under various footwear material, floor, and contamination conditions. Wider tread grooves resulted in higher COF values with a few exceptions especially on oil contaminated floor. Stepwise regression was performed to establish a linear regression model between COF and the tread groove width under footwear material/floor/liquid-contamination conditions. A seven-independent-variable model with an adjusted R^2 of 0.74 was obtained. The lack of fit test result for the model was significant at p<0.0001, indicating that the model adequately fit the friction measurement data.