Oscillatory sliding in the presence of asymmetric friction

Asymmetric friction corresponds to the case when different magnitudes of friction resist sliding in opposing directions. Asymmetric friction can also emerge in anisotropic solids (e.g. rocks) in sliding over fractures with an anisotropic face whose axis of anisotropy is inclined to the direction of sliding and constrained in the normal direction. It can therefore be important in geotechnical applications. Asymmetric friction can also be engineered using anisotropic blocks with an inclined anisotropy axis and used for designing new hybrid or metamaterials. Oscillations of a mass with asymmetric friction can be categorised under one of the following three cases: (1) steady state oscillations in the low friction direction, (2) oscillations in the low friction direction, with decreasing amplitude until the mass becomes stationary, and (3) stick-slip-type movement only in the low friction direction until the mass becomes stationary. In the case of high degree of asymmetric friction such that sliding in the hard direction is impossible, the spectra show peaks at both even and odd multiples of driving frequency.(c) 2022 Elsevier B.V. All rights reserved.