The Earthquake Engineering Online Archive

Seismic behavior and design of semi-rigid steel frames

Nader, Marwan N.; Astaneh-Asl, Abolhassan

UCB/EERC-92/06, Earthquake Engineering Research Center, University of California, Berkeley, 1992-05, 380 pages (517.5/N23/1993)

Steel structures are constructed using three types of beam-to-column connections: rigid, semi-rigid, and simple. While the use of rigid connections is allowed in steel structures in seismic zones, the use of semi-rigid connections is not recommended by current design codes. This recommendation is based on two uncertainties: (1) whether semi-rigid connections will be capable of supplying the rotational ductilities and the maximum plastic rotations required in the event of a severe earthquake; (2) whether inter-story drifts of steel structures built with semi-rigid connections exceed the elastic and inelastic allowable drift limits. The effect of connection flexibility and strength on the dynamic behavior of steel structures was investigated in a combined experimental and analytical research program. In the experimental approach, a single-story structure was constructed such that the connections could be changed from simple to semi-rigid and finally to rigid connections. In the analytical part of the program, a static equivalent lateral force procedure for semi-rigid frames is developed.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-92-06.pdf (22 MB)