Cyclic tests for welded-plate sections with end-plate connections

Welded-plate beams and columns are widely used as elements of moment-resisting frames. Due to the possibility of producing variable cross-sections along the beam or column length so as best to fit the stress condition, plate sections can be most economically designed in the critical cross-sections and result in savings of steel. In recent years, bolted beam-to-column connections, especially end-plate types, have increased in popularity. End-plate beam-to-column connections also provide a viable alternative for moment-resisting frames in seismic design. This study describes an investigation into the effect on cyclic load of the gap between the end plate and the column flange (filled with an I-shaped element; i.e., beam section) on the performance of the connection consisting of welded-plate beam and column sections. In the design of the test specimens, the strength of the panel zone was deliberately changed by altering its thickness, to reduce the risk of shear failure in the panel zone. The thickness of the panel zone was selected as twice the thickness of the column web to minimize deformation in the panel zone of the column, thereby confining the cyclic behaviour to the connection elements. This paper reports on an experimental study of the extended end-plate connections. The comparison between the standard end-plate connection and the innovative end-plate connection is made using the test results. It is concluded that the innovative end-plate connection can achieve a good performance.