An Experimental Investigation of End Plate Connections

Abstract

The results of an experimental investigation of end plate connections of various thicknesses welded to 10 WF21 and 12 WF27 beams and connected to various stiffened and unstiffened 8 WF columns are reported. Moment-rotation curves have been obtained for all connections tested and these have been compared to determine the effects on connection performance of the parameters of end plate thickness, column section, and column stiffener plates. Yield beam lines, representing first yield in a uniformly loaded beam, were drawn to obtain the connection moment at the yield beam line. The value of this moment indicated that the connections behaved semi-rigidly and was used in the comparison of various connections. It was observed that the thicker the end plate, the more rigid the connection and the greater the effect of column stiffeners on the rigidity of the connection. For an end plate connection of a particular width and depth connected to a particular column, there is a limiting moment which such a connection can sustain at the yield beam line, regardless of the thickness of end plate used. This limiting effect is due to deformation of the column section, specifically, of the column flange. Column stiffener plates increased the rigidity of all connections primarily by restraining the deformation of the column flanges adjacent to the tension flanges beams. Column stiffeners prevented column web bucking, however the column web buckles which developed in these tests were initiated at rotations greatly exceeding those expected in structural forms.