Friction coefficient of sliding isolators in icing conditions

Abstract

This paper investigates the variation in static friction coefficient of a double curved surface slider (DCSS) due to low temperature exposure. In the experimental campaign, a full-scale DCSS was subjected to displacement controlled cyclic motions after exposure to different temperatures (20, 0 and −20 °C) for different levels of exposure times (3, 12 and 24 hrs). Tests were repeated for several normal stresses (40, 60 and 80 MPa) and maximum loading velocities (250, 500 and 750 mm/s). Force-displacement curves obtained from the tests were used to calculate static friction coefficients. It is revealed that exposure of DCSS to low temperature leads to formation of an ice layer on the sliding surface. The corresponding sliding is no more a function of properties representative of dry-dry friction, but the ice layer behaves as a lubricant. Thus, static friction coefficient decreases in case of an ice layer on the sliding surface.