Cover-plate and flange-plate steel moment-resisting connections

Nonlinear finite-element modeling of steel moment-resisting connections reinforced with steel plates was undertaken as part of the second phase of the SAC project. Five cover-plate and five flange-plate connections of W14 × 176 columns to W30 × 99 beams were studied. Connections reinforced with cover plates or flange plates will perform substantially better than unreinforced connections. Flange-plate connections are likely superior to cover-plate connections. Rectangular reinforcing plates are superior to trapezoidal shaped plates. Three-sided fillet welds should be used to join reinforcing plates to beam flanges. Bracing the beam flanges outside the plastic hinge remote from the column face to delay lateral-torsional buckling is not necessary. Beam web reinforcement at the column face does not affect the transfer of shear force from the reinforced beam to the column. Beam theory should not be used to estimate stresses in reinforced connections.