The Earthquake Engineering Online Archive

Experiments on eccentrically braced frames with composite floors

Ricles, James M.; Popov, Egor P.

UCB/EERC-87/06, Earthquake Engineering Research Center, University of California, Berkeley, 1987-06, 324 pages (530/R52/1987/v.1)

An experimental study on the cyclic behavior of short links in eccentrically braced steel frames (EBFs) with composite floors is described in which eight tests were performed on two-thirds scale subassemblies consisting of floor beams of EBFs. Two of the specimens were bare steel and the remaining six consisted of steel sections with a composite floor slab. The results of each test are analyzed to determine the increase in cyclic link capacity due to composite action, whether cyclic web buckling in composite links can be inhibited using bare steel link design criteria, and the extent of participation and damage of the concrete floor slab under extreme loading. The interaction between the floor beam and slab in EBFs with composite floor systems is also analyzed. An analytical procedure is developed for determining the effective slab width and moment of inertia of composite floor beams in EBFs, taking into account orthotropic floor slab and beam flexural properties. The accuracy and reliability of the method are tested in an analysis of several test specimens; additional analyses are reported to demonstrate the effects of orthotropic slab behavior and the beam spacing-to-span ratio. See also the companion report, "Dynamic analysis of seismically resistant eccentrically braced frames," by Ricles and Popov, June 1987 (UCB/EERC-87/07).

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-87-06.pdf (44 MB)