NEHRP Clearinghouse
- Title
- Concentrically Braced Frames and Eccentric Bracing Systems. Proceedings of the National Meeting of the Universities Council for Earthquake Engineering Research (4th), Held at University of British Columbia, Vancouver, British Columbia, Canada on June 28-29, 1976.
- File
- PB289420.pdf
- Author(s)
- Roeder, C. W.; Popov, E. P.; Bouwkamp, J. G.
- Source
- National Science Foundation, Washington, DC. Applied Science and Research Applications., June 29, 1976, 6 p.
- Abstract
- The progress of two investigations into the cyclic behavior of two structural steel bracing systems is reported. In one study the centerlines of beams, columns, and braces meet at each joint resulting in concentrically braced frames. Three one-half scale identical braced frames have been constructed, two of which were tested; the third is being prepared for the next experiment. In the first experiment an attempt to determine the static capacity of the frame was made; in the second, progressively increasing completely reversed cyclic displacements were applied; in the third test, cyclic displacements with a bias in one direction will be applied. In the eccentric bracing systems study, braces are deliberately made eccentric with respect to the intersection of the beam-column axes. There are strong indications that bracing systems with eccentric joints provide good energy dissipation characteristics. The results of experiments with symmetric K-braces in which large eccentricities were introduced at the panel centerline led to good results. Inverted Y-braces offer another possibility. In this investigation a detailed study of the eccentric bracing configuration is pursued as being particularly well suited to American construction practice. However, since the inelastic activity occurs near the beam-column connection, this design requires careful scrutiny. Common to both the concentrically braced and eccentric bracing systems studies, the development of more accurate cyclic constitutive relations for inelastic behavior of structural steel is also being pursued.
- Keywords
- Seismic design; Earthquake resistant structures; Steel construction; Framed structures; Bracing; Buildings; Earthquake engineering; Cyclic loads; Dynamic structural analysis