DAMPING IN BOLTED BEAM-COLUMN CONNECTIONS UNDER PULSATING LOADS.

Moment resistant steel beam-column connections using endplates and high strength friction grip bolts have been tested under both static and pulsating loads to determine their energy absorption characteristics. The effect of endplate thickness on damping capacity has been considered for a constant bolt diameter and member cross-section. Six specimens, two each made using 20 mm, 16 mm, and 12 mm thick endplates were tested - three under static loads and the other three under pulsating loads. An optical technique was used for the measurement of rotations of the beam and column. Loss of bolt tension under pulsating loads was also considered. The use of a flexible endplate capable of transferring the full plastic moment of the beam is recommended for these connections.