FRICTION MEASUREMENT DURING FREE VIBRATION
1 online resource (111 pages) : PDF
University of North Carolina at Charlotte
Friction is a key consideration in the behavior of many dynamic systems. However, modeling friction behavior accurately remains an engineering challenge. Current friction measurement approaches are limited to application specific tests that attempt to mimic physical situations. Furthermore, these tests are typically accompanied by large uncertainties (approximately parts in 102). This research presents a new approach to determine friction behavior that uses velocity measured during free vibration to quantify the energy dissipation in sliding friction contacts. A flexure based friction measuring machine (FMM) was used to conduct friction tests at multiple initial energy input levels. A single parameter Coulomb friction model was used to determine the average dynamic coefficient of friction for a friction contact pair consisting of a polytetrafluouroethylene (PTFE) pin and a polished steel counterface. The FMM data was also used to study other friction behaviors that have been experimentally observed in prior work, including the Stribeck effect and non-reversible friction. A three parameter dynamic friction model was used to demonstrate the nonlinear dependence of friction on velocity as a system transitions from the stick to slip regimes (Stribeck effect). The presence of non-reversible friction behavior was tested by sectioning the single dynamic coefficient of friction into two components, one for increasing velocity and one for decreasing velocity. Results showed that the friction coefficient was larger for accelerating motion than for decelerating motion.
ENERGY RATEFREE VIBRATIONFRICTION MEASUREMENTFRICTION MODELING
Schmitz, TonyZiegert, JohnCherukuri, Harish
Thesis (M.S.)--University of North Carolina at Charlotte, 2018.
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). For additional information, see http://rightsstatements.org/page/InC/1.0/.
Copyright is held by the author unless otherwise indicated.