Experimental Verification of an Improved Elastic-Plastic Static Friction Model Including Roughness Effects

An experimental study was performed to measure the static friction coefficient under different experimental conditions. These include different surface roughness conditions, the effect of dwell time, the effect of acceleration (sliding velocity) as well as the presence of traces of lubricant and wear debris at the interface. The static friction tester provides accurate measurement of friction, normal and lateral forces at the interface (using a high dynamic bandwidth piezoelectric force transducer) as well as precise motion control and measurement of the interface motion. The experimental measurements were subsequently compared with an improved elastic-plastic rough surface static friction model, and it was found that the model captures the experimental measurements well, especially in terms of surface roughness. However, the data also shows the limitations of the model as it fails to accurately capture the effects of experimental conditions such as the presence of wear debris and start up velocity.