CONICET | Buscador de Institutos y Recursos Humanos

We perform experiments to determine the critical moment for movement initiation of a millimeter bead placed on a rotating rough surface. The corresponding critical angular velocities are measured for glass and stainless steel ball bearings over two different rough surfaces made with glued glass beads. A basic theoretical analysis is developed to explain the observed results. Although the expectation of a simple approach considering the presence of the obstacles offered by the rough surface could be enough to describe the problem, we prove here that the sole consideration of these obstacles, and even the friction, are not enough to explain the results in the range of a few millimeter glass particles. For the cases where the thermodynamic work of adhesion between surfaces has a significant value, the adhesion forces have to be taken into account in the force balance for particle detachment. This effect is determinant for describing theoretically and numerically the dynamic of millimeter particles.

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