The Earthquake Engineering Online Archive

Structural steel bracing systems: behavior under cyclic loading

Popov, Egor P.; Takanashi, Koichi; Roeder, Charles W.

UCB/EERC-76/17, Earthquake Engineering Research Center, University of California, Berkeley, 1976-06, 81 pages (515/P65/1976)

A survey is made of existing literature on the performance of steel braced frame structures under cyclic excitations. Particular emphasis is placed on inelastic behavior under extreme credible excitations which may occur during a severe earthquake. The experimental and analytical studies of the behavior of an individual brace are described. The effect of the individual braces on the behavior of the entire structural system is then brought out. The behavior of a concentrically braced frame is discussed with respect to dynamic response to given excitations as well as its quasistatic hysteretic behavior under cyclic load. The advantages and limitations of the two possible approaches to design and correlations are indicated. The overall problem is very complex and has not been completely resolved, but a number of plausible design concepts have been advanced. These are reviewed in the report. Most of these are based on static methods of analysis and are intended to assure good dynamic performance of the structure. These approaches are not a substitute for dynamic analysis, but they help simplify the design procedure. Several design concepts, such as the eccentrically connected braced frame, show that braced frames can perform well under extreme excitations. Finally, the limitations of current knowledge are summarized and recommendations for further research are made.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-76-17.pdf (5 MB)