The Earthquake Engineering Online Archive

Dynamic analysis of seismically resistant eccentrically braced frames

Ricles, James M.; Popov, Egor P.

UCB/EERC-87/07, Earthquake Engineering Research Center, University of California, Berkeley, 1987-06, 358 pages (530/R52/1987/v.2)

This report deals with the nonlinear analysis of eccentrically braced steel frames (EBFs) for cyclic static and dynamic loading conditions. It is a companion report to "Experiments on eccentrically braced frames with composite floors," by Ricles and Popov, June 1987 (UCB/EERC-87/06). Two analytical models are developed using a finite element stress resultant formulation for performing static and dynamic nonlinear analyses. The first element is used to model links in EBFs; the second, to model composite floor beams outside the link, accounting for moment-axial force interaction and the cyclic effects of composite action in a practical manner. Three numerical examples are presented. In the first two examples, a bare steel and composite link specimen of the experimental study are analyzed. The third example involves an analysis of a previously tested EBF specimen. Results are compared with the experimental behavior related to the three examples to illustrate the reliability and accuracy of the elements in predicting local link behavior as well as global frame response. Seismic assessment of EBFs designed by plastic design principles is also investigated.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-87-07.pdf (17 MB)