Tribological assessment of sliding pairs under damped harmonic excitation loading based on on-line monitoring methods

Tribological properties of the working surfaces under damped harmonic excitation (DHE) loading are experimentally evaluated. Tribological tests under DHE loading produced by a spring-connecting weight system were capable to monitor friction with a force sensor and to analyze wear processes by an on-line visual ferrography system, respectively. Effects of different spring-connecting loads and various excitation intervals on the tribological behavior were investigated. Results indicated the existence of an appropriate spring-connecting load to give low coefficient of friction. High excitation frequency could help to accelerate the early completion of running-in process, but long excitation intervals could aggravate wear rate in the running-in period. Main surface damages or wear modes were identified as the consequence of fatigue, side flow, and plowing to generate grooves under various DHE loadings.