Moment-rotation characteristics of bolted beam-column connections

Abstract

This paper describes an experimental investigation into the moment-rotation characteristics of bolted end plate beam-to-column connections. Eight specimens of beam-column connections have been tested under gradually increasing static loads. Parameters such as end plate thickness, bolt diameter and beam length were varied for a constant beam and column cross-section. An optical technique was adopted for the measurement of rotations of the beam and the column. In the elastic range, the joints have low rotational capacity, but in the post-elastic range (around the nominal moment of the beam) the rotational capacity of the joints increases and the design of connections using a semi-rigid method of design may be a better approximation to the actual behaviour. Analysis using semi-rigid connections in frames was introduced in codes in the UK in the 1930s following reports from the Steel Structures Research Committee, but this method did not gain popularity because of the large computational effort involved. However, with the current easy access to computers, it should be possible to analyse frames using semi-rigid connections provided well-documented moment-rotation curves are available for the connections.