Investigation of the friction coefficient of sliding isolators in iced conditions

This paper investigates the effect of the formation of ice on the coefficient of friction of sliding isolators. A full-scale sliding isolator was subjected to displacement-controlled cycles motions after exposure to temperatures of either 0 °C or -20 °C for different durations (3, 12 and 24 hrs). The tests were repeated at several pressures and velocities, and the obtained force-displacement curves are used to calculate static and dynamic friction coefficients. Exposure to low temperature leads to formation of an ice layer on the sliding surfaces which behaves as a lubricant. Thus, static friction coefficient decreases with respect to ambient temperature. Such a conclusion is contrary to the bounding analysis design approach of isolation systems where the low temperature exposure is assumed to be considered as an upper bound condition.