INFLUENCE OF MICROSTRUCTURE SHAPE, NON-NEWTONIAN LUBRICANT AND THERMAL EFFECTS ON MICROSTRUCTURED SURFACES IN ROLLING-SLIDING EHL CONTACT
This presentation focuses on the simulation of microstructured surfaces in elastohydrodynamic lubrication regime. It will be analyzed how microstructures influence the lubricant film formation and mixed friction, focusing on microstructure shape, non-Newtonian lubricant and thermal effects. First, slide to roll ratio (SRR) and varying microstructure cross sections are discussed. A benefit of anti-symmetric structures for fluid film build-up and reduced mixed friction is shown. Second, many engineering lubricants show a non-Newtonian behavior. In unstructured EHL contacts this can lead to a reduction of pressure spike and minimum film thickness depending on the shear thinning behavior of the lubricant. Similar effects appear at the microstructure boundaries where an additional pressure spike is apparent. Finally thermo-elastohydrodynamic simulations are shown. Around the microstructures an increase in lubricant temperature is present reducing maximum pressure and film thickness.