Prequalification of Steel Moment-Frame Connection Performance

Welded-flange/bolted-web connections were damaged during the Northridge earthquake, and the SAC Steel Project was funded by the Federal Emergency Management Agency to find solutions to the problems caused by this damage. The Connection Performance Technical Advisory Panel was one of several groups completing the project research, and this group examined all connection performance issues. Many connections were evaluated, and some were prequalified for future use without detailed testing or evaluation. This prequalification criteria and the methods used to satisfy the criteria are described. Some connections that satisfy the prequalification criteria are summarized and the general basis for the prequalification limits are noted. Prequalification requires an adequate experimental database for understanding and evaluating all yield mechanisms and failure modes for each connection type. The concept of the yield mechanisms and failure modes, and the application of the experimental data toward meeting the prequalification requirements are described. A wide range of connections including fully bolted connections, welded connections, and a range of partial-strength and partial-stiffness connections are included.