Structural damping in bolted beam column connections

Moment resistant steel beam column connections using end plates and high strength friction grip bolts have been tested both under static and pulsating loads with an aim to determine the energy absorption characteristics. The beam and column sections has been kept constant in all specimens, but 3 different diameter (16, 20 and 24mm) bolts were used with 16 and 20mm thick end plates. The connections were designed using the plastic method according to the Australian, design of structural connections, (standardised connections manual - part b). An optical technique was used for the measurement of displacements. The damping factors have been evaluated for all specimens tested both static and pulsating loads. Bolt tension losses (relaxation losses) were also monitored under pulsating loads using 2 strain gauged bolts in each specimen (a).