Analyzing Steel moment-Resisting Connections Using Finite Element Modeling

December 30, 2009
Publication: Computational Structural Dynamics and Earthquake Engineering p 363-376
Author(s): Adan, Scott M. Pantelides C.P. Reaveley L.D.

Abstract for Chapter 23: In seismic structural design and rehabilitation deviations from the common practice require testing. The AISC Seismic Provisions for Structural Buildings (American Institute of Steel Construction 2005) recommend that usage and sizing of beam flange continuity plates across the column web shall be based on tests. The FEMA 350 Recommended Seismic Design Criteria (Federal Emergency Management Agency 2000) state that unless project-specific testing is preformed to demonstrate that continuity plates are not required, moment-resisting connections should be provided with continuity plates when the thickness of the column flange is below a minimum value. Similarly, in order to quality any new connection type for inclusion in the AISC Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications (American Institute of Steel Construction 2006), testing has to be carried out to validate the design concept and to satisfy minimum performance criteria on strength and interstory drift angle capacity. In this paper, nonlinear finite element analyses are performed to establish a correlation between measured and computed responses of two steel connections: (1) the reduced beam section (RBS) moment connection without continuity plates, and (2) the bolted bracket (BB) moment connection. The connections were tested using cyclic quasi-static displacements applied at the beam tip. Comparisons of measured and computed responses showed good correlation. Further nonlinear finite element analyses resolved the issue of when continuity plates are necessary for RBS connections, and whether the bottom-only BB connection is an efficient retrofit scheme.

Services: Structural Design