A Statistical Approach for Improving the Accuracy of Dry Friction Coefficient Measurement

Tribological tests are adopted to estimate the kinetic friction coefficient of the material of interest according to the ASTM standard. Typically, for the measurement process, several replicas as well as a postprocessing data treatment are necessary to take into account the observed casual variability of the measurand. This paper describes a novel statistical approach aiming to highlight the most significant time intervals during each test replica. The experimental activity has been carried out with reference to the ball-on-flat configuration of the tribometer in order to verify the suggested procedure in terms of both accuracy and reliability. Numerical simulation and comparison of the measurement results with the output of a different outlier detection algorithm are also included to show the improvement allowed by the authors’ proposal about the dry friction coefficient measurement.