ABSTRACT
This study investigates the effect of normal load and displacement rate on the micromechanical shear behavior of various interface contacts using a particle-on-disc tribometer. Experiments were conducted with different normal loads (5 N to 80 N) and displacement rates (0.5–16 mm/min) to assess the frictional behavior between discrete particles and smooth continuum surfaces. Stainless steel and geomembranes were used to evaluate the influence of continuum material type on frictional response. The results indicate that shear force increases with normal load for both interface types. Geomembranes exhibit a significantly higher frictional response, with the coefficient of friction for geomembranes typically 1.5 to 2 times greater than that for stainless steel for similar testing conditions, owing to enhanced surface deformation and increased contact area. The coefficient of friction increases with normal load, especially for geomembrane contacts. Higher displacement rates reduce the coefficient of friction, highlighting the importance of material properties, surface characteristics, and operational conditions in geotribology. These findings emphasize the critical role of tribological factors in understanding and optimizing interface behavior.
