Partial safety factors and overstrength coefficient evaluation for the design of connections equipped with friction dampers

In this paper, the evaluation of the partial safety factors and of the overstrength coefficient needed to account for the influence of random material variability in the seismic design of dissipative connections equipped with friction dampers is reported. The computation of this coefficient has been carried out by means of a probabilistic approach taking into account different sources of randomness. These are the random variability of the friction coefficient of the pads equipping the damper and the randomness of the bolts preload due to the control of the tightening. Therefore, the aim of the work is the calibration of a local hierarchy criterion able to assure, with a given probability, that the friction connection is subjected to sliding while the beam end remain in elastic range. Finally, partial safety factors to be used in the design of these friction connections are proposed.