System Reliability Benefits of Repetitive Framing in Cold-Formed Steel Floor Systems
Publication: Journal of Structural Engineering
Volume 144, Issue 6
Abstract
Typical cold-formed steel floor systems involve many repetitive joist members laid in parallel, yet the design specifications are based upon the reliability of individual members and fail to account for the potential benefits imparted by repetitive framing. A repetitive member factor, similar to that used in the United States National Design Specifications (NDS) for wood, could be used in cold-formed steel (CFS) design to recognize these benefits and allow for more economical and efficient design that does not compromise safety. This paper introduces and validates procedures based on Monte Carlo simulation for assessing the performance of repetitive floor systems under current code assumptions, and elastic and inelastic load redistribution mechanisms, and uses these procedures to examine two floor systems of varying complexity. Load redistribution is found to provide a benefit of at least 30% to the capacity of the floor system based on a target reliability index of 2.5 and therefore justifies applying a 1.25 factor to the design of joist capacity for the systems studied.
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Acknowledgments
The financial and in-kind support of the American Iron and Steel Institute is gratefully acknowledged, as is the in-kind support of NBM Technologies and the financial support provided by the United States National Science Foundation through grants CMMI-1301033, 1301001, and 1300484. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the American Iron and Steel Institute, NBM Technologies, or the National Science Foundation.
References
ABAQUS version 6.13 [Computer software]. Dassault Systèmes, Waltham, MA.
Agarwal, A., and Varma, A. H. (2014). “Fire induced progressive collapse of steel building structures: The role of interior gravity columns.” Eng. Struct., 58, 129–140.
AISI (American Iron and Steel Institute). (2012). “North American specifications for the design of cold-formed steel structural members.” AISI S100-12, Washington, DC.
ANSI and AWC (American National Standards Institute and American Wood Council). (2012). “National design specifications for wood construction.” ANSI/AWC NDS 2012, Leesburg, VA.
ASCE and SEI (Structural Engineering Institute). (2010). “Minimum design loads for buildings and other structures.” ASCE/SEI 7-10, Reston, VA.
ASCE and SEI (Structural Engineering Institute). (2016). “Minimum design loads for buildings and other structures.” ASCE/SEI 7-16, Reston, VA.
Ayhan, D., and Schafer, B. W. (2017). “Characterization of in-plane backbone response of cold-formed steel beams.” J. Const. Steel Res., 132, 141–150.
Chatterjee, A. (2016). “Structural system reliability with application to light steel-framed buildings.” Ph.D. dissertation, Virginia Polytechnic Institute, Blacksburg, VA.
Chatterjee, A., Arwade, S. R., Schafer, B. W., and Moen, C. D. (2017). “System reliability of floor diaphragms framed from cold-formed steel with wood sheathing.” J. Struct. Eng., 04017208.
Collins, M., Kasal, B., Paevere, P., and Foliente, G. C. (2005). “Three-dimensional model of light frame wood buildings. I: Model description.” J. Struct. Eng., 676–683.
Dubina, D. (2008). “Behavior and performance of cold-formed steel-framed houses under seismic action.” J. Const. Steel Res., 64(7–8): 896–913.
Ellingwood, B. R., and Kinali, K. (2009). “Quantifying and communicating uncertainty in seismic risk assessment.” Struct. Saf., 31(2), 179–187.
Fiorino, L., Della Corte, G., and Landolfo, R. (2007). “Experimental tests on typical screw connections for cold-formed steel housing.” Eng. Struct., 29(8), 1761–1773.
Foschi, R. O., and Yao, F. Z. (1989). “Reliability analysis of wood I-joists.” Can. J. Civ. Eng., 20(4), 564–573.
Fülöp, L. A., and Dubina, D. (2004). “Performance of wall-stud cold-formed shear panels under monotonic and cyclic loading. Part II: Numerical modelling and performance analysis.” Thin-Walled Struct., 42(2), 339–349.
Gad, E. F., Duffield, C. F., Hutchinson, G. L., Mansell, D. S., and Stark, G. (1999). “Lateral performance of cold-formed steel-framed domestic structures.” Eng. Struct., 21(1), 83–95.
Galambos, T. V., Ellingwood, B. R., MacGregor, J. G., and Cornell, C. A. (1982). “Probability based load criteria: Assessment of current design practice.” J. Struct. Div., 108(5), 959–977.
Hendawi, S., and Frangopol, D. M. (1994). “System reliability and redundancy in structural design and evaluation.” Struct. Saf., 16(1–2), 47–71.
Iuorio, O., Fiorino, L., and Landolfo, R. (2014). “Testing CFS structures: The new school BFS in Naples.” Thin-Walled Struct., 84, 275–288.
Izzuddin, B. A., Vlassis, A. G., Elghazouli, A. Y., and Nethercot, D. A. (2008). “Progressive collapse of multi-storey buildings due to sudden column loss—Part I: Simplified assessment framework.” Eng. Struct., 30(5), 1308–1318.
Landolfo, R., Fiorino, L., and Della Corte, G. (2006). “Seismic behavior of sheathed cold-formed structures: Physical tests.” J. Struct. Eng., 570–581.
Li, Y., Shen, S., Yao, X., Ma, R., and Liu, F. (2012). “Experimental investigation and design method research on low-rise cold-formed thin-walled steel framing buildings.” J. Struct. Eng., 818–836.
Madsen, R. L., Nakata, N., and Schafer, B. W. (2012). “CFS-NEES building structural design narrative.”, CFS-NEES: Advancing Cold-Formed Steel Earthquake Engineering, Baltimore.
MATLAB [Computer software]. MathWorks, Natick, MA.
McGuire, R. K., and Cornell, C. A. (1974). “Live load effects in office buildings.” J. Struct. Div., 100(7), 1351–1366.
Moses, F. (1982). “System reliability developments in structural engineering.” Struct. Saf., 1(1), 3–13.
Nakata, N., Schafer, B. W., and Madsen, R. L. (2012). “Seismic design of multi-story cold-formed steel buildings: The CFS-NEES archetype building.” Proc., 2012 Structures Congress, ASCE, Chicago, 1507–1517.
Peterman, K. (2014). “Behavior of full-scale cold formed steel buildings under seismic excitations.” Ph.D. dissertation, Johns Hopkins Univ., Baltimore.
Peterman, K., Schafer, B. W., Madsen, R. L., Buonopane, S., and Nakata, N. (2014). “Experimental performance of full-scale cold-formed steel buildings under seismic excitations.” Dataset. Network for earthquake engineering simulation (NEES), Purdue Univ., West Lafeyette, IN.
Rashedi, R., and Moses, F. (1988). “Identification of failure modes in system reliability.” J. Struct. Eng., 292–313.
Rosowsky, D., and Ellingwood, B. (1991). “System reliability and load sharing effects in light frame wood construction.” J. Struct. Eng., 1098–1116.
Rosowsky, D., and Ellingwood, B. (1992). “Reliability of wood systems subjected to stochastic live loads.” Wood Fiber Sci., 24(1), 47–59.
Rosowsky, D. V., and Yu, G. (2004). “Partial factor approach to repetitive-member system factors.” J. Struct. Eng., 1829–1841.
Schafer, B. W. (2015). “NEESR-CR: Enabling performance-based seismic design of multi-story cold-formed steel structures.” ⟨www.ce.jhu.edu/cfsnees⟩ (May 12, 2015).
Serrette, R., Encalada, J., Juadines, M., and Nguyen, H. (1997). “Static racking behavior of plywood, OSB, gypsum, and fiberboard walls with metal framing.” J. Struct. Eng., 1079–1086.
Smith, B. H., Arwade, S. R., Schafer, B. W., and Moen, C. D. (2016). “Design component and system reliability in a low-rise cold-formed steel framed commercial building.” Eng. Struct., 127, 434–446.
Verrill, S. P., and Kretschmann, D. E. (2010). “Repetitive member factors for the allowable properties of wood products.”, U.S. Dept. of Agriculture, Forest Service, Forest Products Laboratory, Madison, WI.
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Published In
Journal of Structural Engineering
Volume 144 • Issue 6 • June 2018
Copyright
©2018 American Society of Civil Engineers.
History
Received: Jun 15, 2017
Accepted: Oct 28, 2017
Published online: Apr 10, 2018
Published in print: Jun 1, 2018
Discussion open until: Sep 10, 2018
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