Traditionally, special steel moment frames are designed so that the beam will yield under large displacement. The yielding of the beam section provides energy dissipation and is designed to ensure the beam-to-column connection is not compromised. The current design philosophy is the product of extensive testing of SMF connections from the findings of the 1989 Loma Prieta and 1994 Northridge earthquakes in California. Figures 1, 2 and 3 are test specimens showing yielding at designated areas of the beam.
Although other bolted connections are being introduced into the market, the Yield-Link moment connection is the simplest connection to design and erect. It is the only connection that used full-frame testing to demonstrate its strength and can be designed without lateral torsional beam bracing.