14.3.1 Beam Limitations

A wide range of beam sizes have been tested by SSDA with the SW connection. The smallest beam tested was a W24x94 (W610x140). The largest was a W36x393 (W920x585). The AISC Seismic Provisions permit limited increases in beam weight and depth compared to the maximum sections tested, and there is no evidence that modest deviations from the maximum tested specimen would result in significantly different performance.

Both beam depth and beam span-to-depth ratios are significant in the inelastic behavior of beam-to-column connections. For the same induced curvature, deep beams will experience greater strains than shallower beams. Similarly, beams with shorter span-to-depth ratios will have a sharper moment gradient across the beam span, resulting in a reduced length of the beam participating in the plastic hinging and increased strains under inelastic rotational demands. The beam-to-column assemblies that were tested by SSDA with the SW connection are given in Table C-14.1, which includes the test interstory drift ratios.

14.3.2 Column Limitations

All of the SW tests have been performed with the beam flange welded to the column flange (i.e., strong-axis connections). The column sizes used in the tests ranged from W14 columns to W30 columns.

The behavior of SW connections with cruciform columns and box columns is expected to be similar to that of a rolled wide-flange column because the beam flanges frame into the column flange and the column panel zone is oriented parallel to that of the beam. For cruciform columns, the web of the cut wide-flange column is welded with a CJP groove weld to the continuous web 1 ft (300 mm) above and below the depth of the frame girder. Given these similarities and the lack of evidence suggesting behavior limit states different from those associated with rolled wide-flange shapes, cruciform and box column depths are permitted equal to those for rolled wide-flange column depths.