We report a surprising hysteretic behavior in the dynamics of a simple one-dimensional nonlinear model inspired by the tribological problem of two sliding surfaces with a thin solid lubricant layer in between. In particular, we consider the frictional dynamics of a harmonic chain confined between two rigid incommensurate substrates which slide with a fixed relative velocity. This system was previously found, by explicit solution of the equations of motion, to possess plateaus in parameter space exhibiting a remarkable quantization of the chain center-of-mass velocity (dynamic pinning) solely determined by the interface incommensurability. Starting now from this quantized sliding state, in the underdamped regime of motion and in analogy to what ordinarily happens for static friction, the dynamics exhibits a large hysteresis under the action of an additional external driving force Fext. A critical threshold value Fc of the adiabatically applied force Fext is required in order to alter the robust dynamics of the plateau attractor. When the applied force is decreased and removed, the system can jump to intermediate sliding regimes (a sort of “dynamic” stick-slip motion) and eventually returns to the quantized sliding state at a much lower value of Fext. Hysteretic behavior is also observed as a function of the external driving velocity.
|Titolo:||Hysteresis from dynamically pinned sliding states|
|Parole Chiave:||Atomic scale friction; Boundary lubrication; Hysteresis; Models of non-linear phenomena; Stick-slip|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||10.1016/j.susc.2007.07.015|
|Appare nelle tipologie:||01 - Articolo su periodico|