Reinforcing of steel moment connections with cover plates: benefits and limitations

Steel moment connections reinforced with cover plates have received considerable attention in the US since the Northridge earthquake, both in laboratory testing and in new steel moment frame construction. This paper presents experimental data on 12 large scale connection test specimens reinforced with cover plates. Ten of the 12 test specimens showed excellent performance, developing large plastic rotations under cyclic load. Two test specimens failed, however, indicating that cover plated connections are not fool-proof. This type of connection has limitations that must be considered in design and construction. The paper provides a critical assessment of cover plated connections, identifying potential benefits as well as concerns and limitations. Design implications of the experimental data are discussed.