The frictional characteristics of rock forming minerals depend on the relative hardness of the asperity and substrate (flat) upon which it slides; an asperity with a scratch hardness less than a polished flat has a lower static coefficient of friction (μs) on that flat than an asperity with a scratch hardness greater than the same flat. Frictional wear associated with the slip of asperities consists of: (1) ploughing by plastic deformation; (2) ploughing by brittle fracture; (3) fracture of the asperity. Stick-slip correlates with ploughing by brittle fracture. Using Griffith's criteria for propagation of flaws, Hertz's analysis for ring cracking and Hamilton and Goodman's analysis for partial ring cracking under an asperity the normal load necessary for crack propagation and thus the onset of stick-slip may be predicted. The propagation of cracks during ploughing by brittle fracture is one mechanism of time-dependent friction.
|Original language||English (US)|
|Number of pages||9|
|Journal||International Journal of Rock Mechanics and Mining Sciences and|
|State||Published - May 1976|
All Science Journal Classification (ASJC) codes
- Geotechnical Engineering and Engineering Geology