Consistent and Simplified Direct Strength Method for Design of Cold-Formed Steel Structural Members under Localized Loading
Publication: Journal of Structural Engineering
Volume 146, Issue 6
Abstract
The direct strength method (DSM) is a newly developed design method for cold-formed steel members due to its reliability and consistency. It has been well developed and incorporated in the North American Specification and the Australian/New Zealand Standard for the design of cold-formed steel members under compression, bending, and recently, in shear. To date, there are no DSM rules for the design of cold-formed members under localized loading resulting in the web-crippling phenomenon. Recent literature has attempted to propose the DSM design equations for four localized loading cases including the interior one-flange (IOF), end one-flange (EOF), interior two-flange (ITF), and end two-flange (ETF) loading cases specified in the design specifications/standards. However, these proposed DSM equations were calibrated differently depending on the types of loading cases and geometric shapes of the cross-sections by varying coefficients and exponents in the DSM equations. In this paper, consistent and simplified DSM equations previously proposed by the authors are explained and calibrated for use in the design specifications/standards. They include new plastic mechanism models developed for determining the yield load and also cover the design of sections in the inelastic reserve range as observed. Detailed explanations of the yield load () component and references to computing the buckling load () component are given. A design example is also included.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors acknowledge funding for this project provided by the Australian Research Council Discovery Project Grant DP110103948. The first author received scholarships provided from Vietnamese Government (VIED 911 scheme) and supplemental scholarship from School of Civil Engineering, the University of Sydney.
References
AISI (American Iron and Steel Institute). 2016. North American specification for the design of cold-formed steel structural members. NAS S100. Washington, DC: AISI.
AS (Standards Australia). 2018. Cold-formed steel structures. AS/NZS 4600. Sydney, Australia: AS.
Bartlett, A. D. 2016. “Web crippling of cold-formed steel with web swage stiffeners subject to interior-two-flange loading.” B.E. thesis, School of Civil Engineering, Univ. of Sydney.
Beshara, B., and R. M. Schuster. 2000. “Web crippling of cold formed steel C and Z sections.” In Vol. 21 of Proc., 15th Int. Specialty Conf. on Cold-Formed Steel Structures. Rolla, MO: Missouri Univ. of Science and Technology.
Dara, M., and C. Yu. 2015. “Direct strength method for web crippling of cold-formed steel C- and Z sections subjected to one-flange loading.” J. Steel Struct. Constr. 1 (1): 4. https://doi.org/10.4172/2472-0437.1000105.
Efendy, W. 2015. “Bearing capacity of cold-formed steel channels subjected to interior one flange loading.” B.E. thesis, School of Civil Engineering, Univ. of Sydney.
Ellingwood, B., T. V. Galambos, J. G. MacGregor, and C. A. Cornell. 1980. Development of a probability based load criterion for American National Standard A58: Building requirements for minimum design loads in buildings and other structures. Gaithersburg, MD: US Dept. of Commerce, National Bureau of Standards.
Hadchiti, M. 2015. “Bearing capacity of cold-formed steel channels subjected to exterior one flange loading.’ B.E. thesis, School of Civil Engineering, Univ. of Sydney.
Hetrakul, N., and W. Yu. 1978. Webs for cold-formed steel flexural members; structural behaviour of beam webs subjected to web crippling and a combination of web crippling and bending. Columbia, MO: Univ. of Missouri.
Htet, A. K. 2016. “Bearing capacity of cold-formed steel channels subjected to end two flanges loading.” M.E. thesis, School of Civil Engieering, Univ. of Sydney.
Keerthan, P., M. Mahendran, and E. Steau. 2014. “Experimental study of web crippling behaviour of hollow flange channel beams under two flange load cases.” Thin Walled Struct. 85 (Dec): 207–219. https://doi.org/10.1016/j.tws.2014.08.011.
Khatale, G. D. 2014. “Bearing capacity of channels with web stiffeners subjected to two-flange loading.” M.E. thesis, School of Civil Engineering, Univ. of Sydney.
Lian, Y., A. Uzzaman, J. B. P. Lim, G. Abdelal, D. Nask, and B. Young. 2016. “Effect of web holes on web crippling strength of cold-formed steel channel sections under end-one-flange loading condition—Part I: Tests and finite element analysis.” Thin Walled Struct. 107: 443–452. https://doi.org/10.1016/j.tws.2016.06.025.
Lian, Y., A. Uzzaman, J. B. P. Lim, G. Abdelal, D. Nask, and B. Young. 2017. “Web crippling behaviour of cold-formed steel channel sections with web holes subjected to interior-one-flange loading condition-Part I: Experimental and numerical investigation.” Thin Walled Struct. 50 (1): 103–112. https://doi.org/10.1016/j.tws.2016.10.024.
Macdonald, M., M. A. Heiyantuduwa Don, M. KoteŁko, and J. Rhodes. 2011. “Web crippling behaviour of thin-walled lipped channel beams.” Thin Walled Struct. 49 (5): 682–690. https://doi.org/10.1016/j.tws.2010.09.010.
Macdonald, M., M. A. Heiyantuduwa Don, and J. Rhodes. 2008. “Web crippling behaviour of thin-walled lipped channel beams subjected to EOF and ETF loading.” In Proc., 19th Int. Specialty Conf. on Cold-Formed Steel Structures. Rolla, MO: Missouri Univ. of Science and Technology.
Morelli, M. 2014. “Bearing capacity of cold-formed steel channels with web stiffeners subjected to interior one-flange loading.” B.E. thesis, School of Civil Engineering, Univ. of Sydney.
Natário, P., N. Silvestre, and D. Camotim. 2015. GBTWEB, GBT-based code for web buckling analysis of members under localised loads. Lisbon, Portugal: Univ. of Lisbon.
Natário, P., N. Silvestre, and D. Camotim. 2016a. “Direct strength prediction of web crippling failure of beams under ETF loading.” Thin Walled Struct. 98 (Jan): 360–374. https://doi.org/10.1016/j.tws.2015.09.012.
Natário, P., N. Silvestre, and D. Camotim. 2016b. “DSM for Web Crippling under two-flange conditions.” In Vol 20 of Proc., CCFSS2016. Rolla, MO: Missouri Univ. of Science and Technology.
Natário, P., N. Silvestre, and D. Camotim. 2017. “Web crippling of beams under ITF loading: A novel DSM-based design approach.” J. Constr. Steel Res. 128 (Jan): 812–824. https://doi.org/10.1016/j.jcsr.2016.10.011.
Nguyen, V. V., G. J. Hancock, and C. H. Pham. 2017a. “Application of the THIN-WALL-2 V2.0 program for analysis of thin-walled sections under localised loading.” In Proc., Int. Conf. CIGOS2017—New Challenges in Civil Engineering. New York: Springer.
Nguyen, V. V., G. J. Hancock, and C. H. Pham. 2017b. “Analyses of thin-walled sections under localised loading for general end boundary conditions. Part I: Pre-buckling.” Thin Walled Struct. 119 (Oct): 956–972. https://doi.org/10.1016/j.tws.2017.01.010.
Nguyen, V. V., G. J. Hancock, and C. H. Pham. 2017c. “Analyses of thin-walled sections under localised loading for general end boundary conditions. Part II: Buckling.” Thin Walled Struct. 119 (Oct): 973–987. https://doi.org/10.1016/j.tws.2017.01.008.
Nguyen, V. V., G. J. Hancock, and C. H. Pham. 2017d. “New developments in the Direct Strength Method (DSM) for design of cold-formed steel sections under localised loading.” J. Steel Constr. 10 (3): 227–233. https://doi.org/10.1002/stco.201710028.
Schafer, B. W., and T. Pekoz. 1998. “Direct strength prediction of cold-formed steel members using numerical elastic buckling solutions.” In Proc., 14th Int. Specialty Conf. on Cold-Formed Steel Structures. Rolla, MO: Univ. of Missouri.
Sundararajah, L., M. Mahendran, and P. Keerthan. 2015. “Experimental studies of lipped channel beams subjected to web crippling under ETF and ITF load cases.” In Proc., 8th Int. Conf. on Advances in Steel Structures. Lisbon, Portugal: University of Lisbon.
Sundararajah, L., M. Mahendran, and P. Keerthan. 2016. “Web crippling capacity of Cold-formed channel sections with and without longitudinal web stiffeners subjected to two-flange load cases.” In Proc., 7th Int. Conf. on Coupled Instabilities in Metal Structures. Baltimore: Johns Hopkins Univ.
Uzzaman, A., J. B. P. Lim, D. Nask, J. Rhodes, and B. Young. 2012a. “Cold-formed steel sections with web openings subjected to web crippling under two-flange loading conditions-part I: Tests and finite element analysis.” Thin Walled Struct. 56 (Jul): 38–48. https://doi.org/10.1016/j.tws.2012.03.010.
Uzzaman, A., J. B. P. Lim, D. Nask, J. Rondal, and B. Young. 2012b. “Web crippling behaviour of cold-formed steel channel sections with offset web holes subjected to interior-two-flange loading.” Thin Walled Struct. 50 (1): 76–86. https://doi.org/10.1016/j.tws.2011.09.009.
Young, B., and G. J. Hancock. 2001. “Design of cold-formed channels subjected to web crippling.” J. Struct. Eng. 127 (10): 1137–1144. https://doi.org/10.1061/(ASCE)0733-9445(2001)127:10(1137).
Information & Authors
Information
Published In
Copyright
©2020 American Society of Civil Engineers.
History
Received: Nov 28, 2018
Accepted: Oct 15, 2019
Published online: Mar 25, 2020
Published in print: Jun 1, 2020
Discussion open until: Aug 25, 2020
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.