Abstract Summary
Applying an oscillatory load is one of the most efficient ways to alter friction forces. Several theoretical and experimental studies on the influence of oscillatory loads on friction have been conducted, investigating the effect of both in-and out-of-plane oscillations for different tribological pairings and ranges of oscillation amplitudes, frequencies, and sliding velocities. However, the effect of external load on the frictional property has been studied with an emphasis on dynamic loads characterized by a high-frequency content, while a clear statement as to what is considered high-frequency is still missing. The common method of analysis for high-frequency is the method of direct separation of motion (MDMS). However, when studying the effect of a general sinusoidal excitation on friction by means of the MDMS, the analytical solutions become cumbersome or even impossible to obtain. Therefore, this study aims to show that a general relation, regardless of the frequency range, accounting for the induced effect of excitation on friction, can be easily obtained by utilizing the mobility transfer function of the linear dynamic system. Besides the study of linear systems, this work also presents the effect of excitation on friction for some nonlinear systems. To solve the case of a nonlinear system, the harmonic balance method will be used. The proposed method will be applied to a classical mass-spring-dashpot system on a moving belt, and Amontons-Coulomb and Stribeck laws will be considered.
