Through-thickness properties of column flanges in welded moment connections

Forty tee-joint specimens were tested to assure that through-thickness stre ngth or ductility of the column flanges is not a potential failure mode for welded moment connections. The specimens were designed with 690-MPa yield- strength pull plates and a high-strength high-toughness double groove shop weld (not representative of structural welds) to attempt to induce through- thickness failures in column flanges. Despite high strain rate, high-heat i nput welds, and several details designed to trigger fractures, only one thr ough-thickness failure occurred. In most cases the pull plates broke, and i n all cases the stress levels exceeded 690 MPa, well above the stress level that could be delivered by structural steel beam flanges. The only specime n fabricated without continuity plates resulted in a through-thickness brit tle fracture of the column flange, although the nominal pull-plate stress w as quite high (698 MPa). The lack of yielding in the through-thickness dire ction can be explained by the existence of triaxial constraint of the colum n flange material.