INVESTIGATION ON STATIC FRICTION COEFFICIENT OF A DOUBLE CURVED SURFACE SLIDER

This paper aims to address the variation in static friction coefficient of a double curved surface slider (DCSS) due to low temperature exposure. Accordingly, a DCSS was subjected to displacement controlled cyclic motions in which various normal stresses (20, 40, 60, 80 MPa) and temperatures (20, 0 and -20°C) were considered to observe the effects of different loading conditions. Full-scale tests were conducted at ESQUAKE Seismic Isolator Test Laboratory of Eskişehir Technical University. Force-displacement curves recorded at each loading sequence were used to define the static friction coefficient (or breakaway friction) of the tested DCSS. Computed static friction coefficients were presented in such a way that the response modification can be compared for each loading parameter. Test results showed that when the temperature decreases static friction coefficient decreases remarkably. Moreover, that reduction in static friction coefficient becomes more pronounced with an increase in normal stress level.