ABSTRACT
This paper presents the results of an experimental study of the seismic performance of improved, unreinforced welded beam-to-column moment connections. The study involved the inelastic cyclic testing of nine full-scale connection specimens to evaluate the effects of weld access hole geometry, panel zone strength, continuity plates, and beam web attachment detail on connection cyclic performance. Tests were also performed on 15 beam tension flange-to-column flange pull-plate specimens to investigate the effects of notch toughness of the filler metal, use of grooved backing bars, and weld reinforcement. It is shown that the use of a notch-tough electrode is the single most important detail that improves connection ductility. Improved access hole details, in conjunction with notch-tough beam flange welds and a beam web groove weld detail is shown to enable a connection to achieve a cyclic plastic rotation more than 3% rads. Based on the results of the research improved guidelines are given for the seismic resistant design of welded connections for steel moment resisting frames.
