Rotational Capacity of Bolted Double-Web-Angle Beam-Column Gravity Connections through Full-Scale Experimental Testing

Double-web-angle beam-column connections are used extensively for gravity framing in steel buildings. Although they are designed to resist shear and to allow rotation, they still possess moment capacity that may contribute to lateral resistance, particularly in extreme-load scenarios. To characterize the nonlinear hysteretic behavior of bolted angle connections subjected to simultaneous gravity shear and rotational demand from the moment frame action, a comprehensive test program was conducted. Eight full-scale beam-column subassemblages of two different geometries were tested to characterize their hysteretic behavior and failure modes in relationship to the following parameters: angle geometry, beam and column section properties, gravity shear load, and loading history. The backbone curve of each test was calibrated numerically to reproduce the connection behavior. Double-web-angle connections exhibited large rotational capacity and stable hysteretic behavior. Their stable hysteretic behavior may be of interest in terms of a reserve capacity because it can provide sufficient rotational capacity to the gravity frame and mitigate building collapse in low-ductility braced frames.