Determining relationships associated with traction of studded footwear on artificial sports surfaces

Traction tests were carried out using a constant speed motor to drag a studded metal sled, acting as a simplified shoe sole, across an artificial surface. The traction force of studded footwear is dependent on a number of variables including stud geometry, turf type, depth of stud penetration and velocity. In order to investigate the significance of each variable on traction, an effort was made to carry out tests in which as many variables as possible were kept constant. This study evaluates the effect of stud depth, cross-sectional area and velocity for cylindrical studs on XL artificial turf. Previous studies have shown that lift forces can arise during such testing causing the sled to rise out of the surface. Therefore, a traction rig, built in-house, has been modified to maintain a constant penetration level during movement. The static traction, dynamic traction and initial loading rate were compared for each stud type. Dynamic traction shows strong dependence on the cross-sectional area of the stud penetrated in the surface. An increase in sled velocity increases dynamic traction but the effect is less severe than stud area. Static traction and loading rate area are influenced similarly to dynamic traction, but the effects are not as significant due to greater uncertainties in these measurements. Such tests have implications on the design of studs in that the change in traction force for proposed subtle geometry changes to studs can be predicted.