Velocity weakening and possibility of aftershocks in nanoscale friction experiments

E. A. JAGLA

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2012 vol. 86 p. 155408 - 155408

1098-0121

We study the frictional behavior of small contacts as those realized in the atomic force microscope and other experimental setups, in the framework of generalized Prandtl-Tomlinson models. Particular attention is paid to mechanisms that generate velocity weakening, namely, a decreasing average friction force with the relative sliding velocity. The mechanisms studied model the possibility of viscous relaxation, or aging effects in the contact. It is found that, in addition to producing velocity weakening, these mechanisms can also produce aftershocks at sufficiently low sliding velocities. This provides a remarkable analogy at the microscale, of friction properties at the macroscale, where aftershocks and velocity weakening are two fundamental features of seismic phenomena.