Modeling of Double-Angle Shear Connections for the Evaluation of Structural Robustness

Improved structural robustness is expected for steel gravity load-resisting frames with double-angle shear connections as compared to single-plate connections, given the larger deformation capacity of the double angle. Detailed models of bolted double-angle beam-column connections have been developed for the purpose of evaluating the structural robustness, or resistance to disproportionate collapse, of steel gravity frames. The detailed models have been validated through comparison with available experimental data. Modeling of double-angle connections requires considerations not needed for single-plate connections, such as a reduced ductility in the "k-area" of the angle. Detailed models of two-bay gravity frames were analyzed under "push-down" loading to simulate a column loss scenario. Results for frames with bolted double-angle and single-plate connections show that the larger deformation capacity of the double-angle connection enables larger vertical loads to be sustained with correspondingly larger connection rotations.