Experimental Investigation of Chevron Concentrically Braced Frames with Yielding Beams
Publication: Journal of Structural Engineering
Volume 142, Issue 12
Abstract
Steel concentrically braced frames designed prior to the implementation of capacity design principles in seismic design provisions may exhibit poor inelastic response under seismic excitation. These older, nonductile concentrically braced frames (NCBFs) used several configurations, with the chevron configuration being one of the most common. The response of chevron-configured NCBFs is unknown, as relatively large axial and flexural demands are imposed on the beam after brace buckling. Current code requirements for special concentrically braced frames (SCBFs) promote full yielding of the braces while the beam remains elastic, but NCBFs develop a mechanism in which the beam yields, deforms plastically, and limits tensile elongation of the brace. However, if ductile, this plastic mechanism may meet current performance limits and not require retrofitting. To examine this issue, four tests of two-story NCBFs were conducted at the National Center for Research on Earthquake Engineering in Taipei, Taiwan. The tests were designed to form a yielding-beam plastic mechanism as opposed to a yielding brace-elastic beam plastic mechanism. The results show the yielding-beam mechanism provided adequate lateral strength and deformation capacity and beams in a chevron configuration are a low priority with regard to retrofit, whereas retrofitting to mitigate brace and connection deficiencies is a high priority. The tests also demonstrate that modern CBFs can sustain lateral force and deformation demands if the yielding-beam, as opposed to yielding-brace, plastic mechanism is formed. The results support the modification of the stringent design requirements for chevron SCBFs.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors gratefully acknowledge the support of the National Science Foundation Grant No. CMMI-1208002. Dr. Joy Pauschke is the Program Officer. AISC, with Tom Schlafly providing oversight, provided independent funding for some of the specimens and material donations. The tests were performed at the NCREE Laboratory in Taipei, Taiwan, and the authors gratefully acknowledge the great assistance and support they provided. This material is also based upon work supported by the National Science Foundation Graduate Research Fellowship (DGE-1256082). The authors are grateful to all of the aforementioned agencies for their support. The opinions and findings expressed here are those of the authors alone and do not necessarily reflect the views of the sponsoring agencies.
References
AISC. (2010a). “Seismic provisions for structural steel buildings.” ANSI/AISC 341-10, Chicago.
AISC. (2010b). “Specification for structural steel buildings.” ANSI/AISC 360-10, Chicago.
ATC (Applied Technology Council). (1992). “Guidelines for cyclic seismic testing of components of steel structures for buildings.”, Redwood City, CA.
Bradley, C., Sizemore, J., Nelson, J., Tremblay, R., Hines, E. M., and Fahnestock, L. A. (2014). “Large-scale testing of low-ductility, concentrically-braced frames.” Structures Congress 2014, ASCE, Reston, VA, 2417–2428.
Foutch, D. A., Goel, S. C., and Roeder, C. W. (1987). “Seismic testing of full-scale steel building—Part I.” J. Struct. Eng., 2111–2129.
Fukuta, T., Nishiyama, I., Yamanouchi, H., and Kato, B. (1989). “Seismic performance of steel frames with inverted V braces.” J. Struct. Eng., 2016–2028.
Goel, S. C. (1992). “Cyclic post buckling behavior of steel bracing members.” Stability and ductility of steel structures under cyclic loading, CRC Press, Boca Raton, FL.
Hsiao, P. C. (2012). “Seismic performance evaluation of concentrically braced frames.” Ph.D. dissertation, Univ. of Washington, Seattle.
ICBO (International Conference of Building Officials). (1985). “Uniform building code.” Whittier, CA.
ICBO (International Conference of Building Officials). (1988). “Uniform building code.” Whittier, CA.
ICBO (International Conference of Building Officials). (1994). “Uniform building code.” Whittier, CA.
Khatib, I. F., Mahin, S. A., and Pister, K. S. (1988). “Seismic behavior of concentrically braced steel frames.”, Earthquake Engineering Research Center, Berkeley, CA.
Lai, J. W., and Mahin, S. A. (2013). “Experimental and analytical studies on the seismic behavior of conventional and hybrid braced frames.”, Pacific Earthquake Engineering Research Center, Berkeley, CA.
Lai, J. W., and Mahin, S. A. (2015). “Strongback system: A way to reduce damage concentration in steel-braced frames.” J. Struct. Eng., 04014223.
Liu, Z., and Goel, S. C. (1988). “Cyclic load behavior of concrete-filled tubular braces.” J. Struct. Eng., 1488–1506.
Lumpkin, E. J. (2009). “Enhanced seismic performance of multi-story special concentrically brace frames using a balanced design procedure.” M.S. thesis, Univ. of Washington, Seattle.
Lumpkin, E. J., et al. (2012). “Investigation of the seismic performance of three-story special concentrically braced frames.” J. Constr. Steel Res., 77, 131–144.
Popov, E. P. (1986). “On California structural steel seismic design.” Proc., 1986 Pacific Structural Steel Conf., New Zealand Heavy Engineering Research Association, Auckland, New Zealand, 7–21.
Rai, D. C., and Goel, S. C. (2003). “Seismic evaluation and upgrading of chevron braced frames.” J. Constr. Steel Res., 59(8), 971–994.
Remennikov, A. M., and Walpole, W. R. (1998). “Seismic behavior and deterministic design procedures for steel V-braced frames.” Earthquake Spectra, 14(2), 335–355.
Roeder, C. W. (1989). “Seismic behavior of concentrically braced frame.” J. Struct. Eng., 1837–1856.
Roeder, C. W., Lumpkin, E. J., and Lehman, D. E. (2011). “A balanced design procedure for special concentrically braced frame connections.” J. Constr. Steel Res., 67(11), 1760–1772.
SEAOC (Structural Engineers Association of California). (1990). “Recommended lateral force requirements and commentary.” Sacramento, CA.
SEAOC (Structural Engineers Association of California). (1996). “Recommended lateral force requirements and commentary.” Sacramento, CA.
Sen, A. D. (2014). “Seismic performance of chevron concentrically braced frames with weak beams.” M.S. thesis, Univ. of Washington, Seattle.
Sloat, D. A. (2014). “Evaluation and retrofit of non-capacity designed braced frames.” M.S. thesis, Univ. of Washington, Seattle.
Tremblay, R., and Robert, N. (2001). “Seismic performance of low- and medium-rise chevron braced steel frames.” Can. J. Civ. Eng., 28(4), 699–714.
Tsai, C. Y., et al. (2013). “Seismic design and hybrid tests of a full-scale 3-story concentrically braced frame using in-plane buckling braces.” Earthquake Spectra, 29(3), 1043–1067.
Uriz, P., and Mahin, S. A. (2008). “Toward earthquake-resistance design of concentrically braced steel-frame structures.”, Pacific Earthquake Engineering Research Center, Berkeley, CA.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 142 • Issue 12 • December 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: May 12, 2015
Accepted: May 1, 2016
Published online: Jul 11, 2016
Published in print: Dec 1, 2016
Discussion open until: Dec 11, 2016
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.