FRICTIONAL CHARACTERISTICS OF TEFLON-STEEL INTERFACES UNDER DYNAMIC CONDITIONS.

An experimental study to assess the frictional characteristics of Teflon-steel interfaces under dynamic conditions is described. Tests were conducted on unfilled Teflon sliding on stainless steel polished to a surface roughness of less than 0. 05 mu m CLA. The bearing pressure was 1. 38, 3. 45 and 6. 9 N/mm**2, the frequency of sliding was 0. 5 and 1 Hz and the acceleration of excitation, imposed by a small shaking table, was between 0. 05 and 0. 5 g. It was found that friction drops with decreases in the acceleration of excitation and drops with increases in the bearing pressure. It was observed that Teflon-steel interfaces have the tendency to slide continuously regardless of the value of acceleration. This is very important in base isolation applications because it prevents high frequency input to the structure.