Hi! A new paper was just published:
Stiff and soft active control of friction by vibrations and their energy efficiency
J. Benad, M. Popov, K. Nakano, V. L. Popov
Forschung im Ingenieurwesen, vol. 82, no. 4, pp. 331-339, 2018
The work builds upon the results of two recent studies on the influence of friction by normal and sideways oscillations. The findings are rewritten to a more compact form and the results for both oscillation modes are presented side by side in a consistent manner. It is shown that the macroscopic coefficient of friction is only a function of a dimensionless sliding velocity and a dimensionless oscillation amplitude for the considered model. Also, the energy efficiency is characterized for both oscillation modes for the first time by comparing the total energy which includes the superimposed oscillations with the energy needed for the motion without the additional oscillations.