Experimental Testing of a Replaceable Brace Module for Seismically Designed Concentrically Braced Steel Frames
Publication: Journal of Structural Engineering
Volume 145, Issue 4
Abstract
For a seismically designed concentrically braced frame with hollow structural sections as braces, the typical connection design consists of a slotted brace that is field welded to a gusset plate. During an earthquake, the brace is expected to buckle out-of-plane and the gusset plate is expected to yield. This makes it difficult to repair or replace the brace and connection, and the out-of-plane brace buckling caused by this connection can also damage surrounding walls and cladding, with potential life safety implications. This paper proposes an alternative connection that is expected to result in reduced erection costs by avoiding site welding, and also to simplify structural repairs following a major earthquake by confining all damage to a replaceable brace module. Additionally, the new connection causes the brace to buckle in-plane during a seismic event, reducing the potential for damage to the surrounding walls and cladding. This paper discusses large-scale quasi-static cyclic testing of eight brace modules with two variations of the new connection, one with a single-shear eccentric splice and the other with a double-sided concentric splice. All tested specimens had the desired failure progression and buckled in-plane, as intended. Bolt slip in the connection had very little effect on the overall force-deflection response after the brace compressive strength degraded to less than the slip load. The brace module was replaced after each test without observable damage outside the module. Although both connection variations behaved in a desirable manner, the single-shear eccentric splice was preferred because of the simpler constructability and improved performance.
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Acknowledgments
Funding for this project has been provided by the National Sciences and Engineering Research Council (NSERC), Ontario Centres of Excellence (OCE), the Canadian Institute of Steel Construction (CISC) and the Ontario Erectors Association (OEA). Fabrication services and consultation were provided by Walters. The authors gratefully acknowledge this support.
References
AISC. 2010. Seismic provisions for structural steel buildings. ANSI/AISC 341. Chicago: AISC.
Astaneh-Asl, A., S. Goel, and R. Hanson. 1985. “Cyclic out-of-plane buckling of double-angle bracing.” J. Struct. Eng. 111 (5): 1135–1153. https://doi.org/10.1061/(ASCE)0733-9445(1985)111:5(1135).
ASTM. 2010a. Standard specification for cold-formed welded and seamless carbon steel structural tubing in rounds and shapes. ASTM A500. West Conshohocken, PA: ASTM.
ASTM. 2010b. Standard specification for structural bolts, steel, heat treated, 120/105 ksi minimum tensile strength. ASTM A325. West Conshohocken, PA: ASTM.
ATC (Applied Technology Council). 1992. Guidelines for cyclic seismic testing of components of steel structures. ATC 24. Redwood City, CA: ATC.
Bruneau, M., C.-M. Uang, and R. Sabelli. 2011. Ductile design of steel structures. 2nd ed. New York: McGraw-Hill.
CSA (Canadian Standards Association). 2013. General requirements for rolled or welded structural quality steel/structural quality steel. G40.20-13/G40.21-13. Mississauga, Canada: CSA.
CSA (Canadian Standards Association). 2014. Limit states design of steel structures. CSA S16. Toronto: CSA.
Davaran, A., A. Gelinas, and R. Tremblay. 2015. “Inelastic buckling analysis of steel X-bracing with bolted single shear lap connections.” J. Struct. Eng. 141 (8): 04014204. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001141.
de Oliveira, C., C. Christopolous, and J. Packer. 2011. “High-strength brace connectors for use in SCBF and OCBF.” In Proc., 80th Annual Structural Engineers Association of California Convention. Sacramento, CA: Structural Engineers Association of California.
de Oliveira, C., J. Packer, and C. Christopolous. 2008. “Cast steel connectors for circular hollow section braces under inelastic cyclic loading.” J. Struct. Eng. 134 (3): 374–383. https://doi.org/10.1061/(ASCE)0733-9445(2008)134:3(374).
Han, S. W., W. T. Kim, and D. A. Foutch. 2007. “Seismic behavior of HSS bracing members according to width-thickness ratio under symmetric cyclic loading.” J. Struct. Eng. 133 (2): 264–273. https://doi.org/10.1061/(ASCE)0733-9445(2007)133:2(264).
Kotulka, B. A. 2007. “Analysis for a design guide on gusset plates used in special concentrically braced frames.” M.A.Sc. thesis, Dept. of Civil and Environmental Engineering, Univ. of Washington.
Lee, K., and M. Bruneau. 2005. “Energy dissipation demand of compression members in concentrically braced frames.” Steel Compos. Struct. 5 (5): 345–358.
Lehman, D., C. Roeder, D. Herman, S. Johnson, and B. Kotulka. 2008. “Improved seismic performance of gusset plate connections.” J. Struct. Eng. 134 (6): 890–901. https://doi.org/10.1061/(ASCE)0733-9445(2008)134:6(890).
NRCC (National Research Council of Canada). 2010. National building code of Canada 2010. NBCC-10. Ottawa: NRCC.
Packer, J., D. Sherman, and M. Lecce. 2010. Steel design guide 24: Hollow structural section connections. Chicago: AISC.
Powell, J. A. 2010. “Evaluation of special concentrically braced frames for improved seismic performance and constructability.” M.A.Sc. thesis, Dept. of Civil and Environmental Engineering, Univ. of Washington.
Roeder, C. W., E. J. Lumpkin, and D. E. Lehman. 2011. “A balanced design procedure for special concentrically braced frame connections.” J. Constr. Steel Res. 67 (11): 1760–1772. https://doi.org/10.1016/j.jcsr.2011.04.016.
Sen, A. D., C. W. Roeder, J. W. Berman, D. E. Lehman, C. H. Li, A. C. Wu, and K. C. Tsai. 2016. “Experimental investigation of chevron concentrically braced frames with yielding beams.” J. Struct. Eng. 142 (12): 04016123. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001597.
Sen, A. D., D. Sloat, L. Pan, C. W. Roeder, D. E. Lehman, and J. W. Berman. 2013. “Evaluation of the seismic performance of two-story concentrically braced frames with weak beams.” In Proc., 5th Int. Conf. on Advances in Experimental Structural Engineering. Taipei, Taiwan: NCREE.
Stevens, D., and L. Wiebe. 2016. “Development of a novel replaceable connection for seismically designed steel concentrically braced frames.” In Proc., 5th Int. Structural Speciality Conf., CSCE 2016. Montreal, Canada: Canadian Society for Civil Engineering.
Takeuchi, T., and R. Matsui. 2015. “Cumulative deformation capacity of steel braces under various cyclic loading histories.” J. Struct. Eng. 141 (7): 04014175. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001146.
Tremblay, R., M. Archambault, and A. Filiatrault. 2003. “Seismic response of concentrically braced steel frames made with rectangular hollow bracing members.” J. Struct. Eng. 129 (12): 1626–1636. https://doi.org/10.1061/(ASCE)0733-9445(2003)129:12(1626).
Tsai, C. Y., et al. 2013. “Seismic design and hybrid tests of a full-scale three-story concentrically braced frame using in-plane buckling braces.” Earthquake Spectra 29 (3): 1043–1067. https://doi.org/10.1193/1.4000165.
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©2019 American Society of Civil Engineers.
History
Received: Dec 20, 2016
Accepted: Sep 10, 2018
Published online: Jan 30, 2019
Published in print: Apr 1, 2019
Discussion open until: Jun 30, 2019
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