Reduction of friction by normal oscillations. I. Influence of contact stiffness

• Published in: Friction Vol. 5; no. 1; pp. 45 - 55
• Main Authors: Popov, M., Popov, V. L., Popov, N. V.
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01-03-2017; Springer Nature B.V; SpringerOpen
• Subjects: active control of friction; Amplitudes; coefficient of friction; Contact; contact stiffness; Corrosion and Coatings; Engineering; Friction; Mechanical Engineering; Nanotechnology; Oscillations; out-of-plane oscillation; Physical Chemistry; Punches; Research Article; Sliding; Sliding friction; Stiffness; Surfaces and Interfaces; Thin Films; Tribology; active control of friction; sliding friction; out-of-plane oscillation; coefficient of friction; contact stiffness
• ISSN: 2223-7690; 2223-7704
• DOI: 10.1007/s40544-016-0136-4

The present paper is devoted to a theoretical analysis of sliding friction under the influence of oscillations perpendicular to the sliding plane. In contrast to previous works we analyze the influence of the stiffness of the tribological contact in detail and also consider the case of large oscillation amplitudes at which the contact is lost during a part of the oscillation period, so that the sample starts to “jump”. It is shown that the macroscopic coefficient of friction is a function of only two dimensionless parameters—a dimensionless sliding velocity and dimensionless oscillation amplitude. This function in turn depends on the shape of the contacting bodies. In the present paper, analysis is carried out for two shapes: a flat cylindrical punch and a parabolic shape. Here we consider “stiff systems”, where the contact stiffness is small compared with the stiffness of the system. The role of the system stiffness will be studied in more detail in a separate paper.