Sliding friction deviating from

The calculated energetics also allow one to estimate the normal load, thereby providing access to the friction coefficient once the friction force is known. This method, albeit crude, has been shown to yield good results when compared with experiments in cases such as graphite sheets sliding past one another.68 However, one should realize that approximations in the determination of the normal load, the assumption that friction only depends on energy barriers, and the lack of a consideration of dynamical aspects of system may lead to significant deviations from experimental results for many other systems. 

Fig. 4 shows the influence of oxygen-plasma treatment of PDMS surface on the measured friction vs. load plots (m = 0.0025 m/s). The friction forces and error bars represent the average kinetic fiiction forces and standard deviations from the fiiction vs. time (or number of rotation) plots for each measurement. A few characteristics are observed. Firstly, the sliding contact of untreated PDMS... 

Friction-induced vibration, in the most general sense, is the deviation from uniform sliding due to the interaction of friction and system dynamics. This can occur due to surface topography. However, the problem which is of the most concern is self-excited oscillations that occur due to a functional dependence of friction with velocity or... 

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