Date of Award
Master of Science
Christian J. Schwartz
Tactile friction which occurs between the surfaces of hand-operated products and the user as well as the user’s perception of surface characteristics are both very important considerations for the function of engineering products. While the use of surface texture is known to greatly influence these properties, the effect of the governing textural parameters on the friction mechanisms between a textured material and a deformable material is poorly understood making it difficult to design textures for specific tactile properties. The ability to model the tactile outcomes for the interaction between a simple textured surface and deformable body would be very beneficial to understanding how friction coefficient and perception of textures are influenced.
Previous studies have measured friction between polymers and textures, obtained qualitative data of subject perceptions of surface topographies, and have used computational simulations to better understand the underlying friction and perception mechanisms. It has previously been hypothesized that the penetration of the deformable material into the valleys of a surface texture drives friction behavior. Two dimensional profiles of simple textures are often examined to more easily isolate the effects of textural parameters. In this investigation, an elastic mechanics based computational model was developed to predict the behavior between a cylindrical deformable material against a rigid body of rectangular grooves. A non-dimensionalized similitude approach was used to investigate the dependence of groove penetration and the number of ridges in contact on groove and ridge dimension, as well as applied pressure and the elastic modulus. The penetration computational results were verified by a macro-scale empirical investigation and groove contact computational results were compared to predictions based on Hertzian contact between a cylinder and a rigid flat plane. It was found that groove and ridge dimensions have a very profound effect on the penetration behavior of the elastomeric body. Smaller grooves and wider ridges resulted in a negligible difference on ridges in contact from the Hertzian contact prediction. However, as groove size increased and ridge width decreased, an empirical computational model was developed which accurately predicted ridges in contact.
Thomas Joseph Wilde
Wilde, Thomas Joseph, "Parametric investigation of the mechanics of soft-body contact with parallel-ridge textured surfaces to understand tactile friction" (2015). Graduate Theses and Dissertations. 14719.