Elevated Temperature Material Degradation of Cold-Formed Steels under Steady- and Transient-State Conditions
Publication: Journal of Materials in Civil Engineering
Volume 25, Issue 8
Abstract
Material properties at elevated temperatures are important factors in the fire safety design and numerical analysis of cold-formed steel structures. Most of the previous research on material properties at high temperatures has adopted the steady-state test method. However, the transient-state test method is more realistic for actual fire conditions. This paper presents a detailed experimental investigation of Q345 cold-formed steel with a nominal yield strength of 345 MPa and a thickness of 1.5 mm under transient- and steady-state conditions. Both the flat and corner parts of Q345 cold-formed steel sections are considered. The results showed that the steady-state method was not equivalent to the transient-state method for Q345 steel; in addition, current standards provided overestimations for the mechanical properties of Q345 steel under elevated temperatures. An empirical equation was proposed to estimate the reduction factors for the yield and ultimate strength and the elastic modulus of Q345 steel under elevated temperatures, where the essential parameters were determined through fitting. The stress-strain relationship of Q345 steel under elevated temperatures was further developed based on the Ramberg-Osgood model, which compared well with the experimental results.
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Acknowledgments
This research was sponsored by the Priority Academic Program Development of Jiangsu Higher Education Institutions, and the Scholarship Award for Excellent Doctoral Students granted by the Ministry of Education, China. The authors thank BlueScope Lysaght Shanghai for supplying the test material. They also thank Mr. Chen Shengming and Mr. Ying Shuiping for providing the experimental devices.
References
ASTM. (2006). “Standard test method for linear thermal expansion of solid materials with a push-rod dilatometer.” ASTM E228-06, West Conshohocken, PA.
British Standards Institution (BSI). (2003). “Structural use of steelwork in building. Code of practice for fire resistant design.” BS 5950-8:2003, London.
Chen, J. (2007). “Behavior of high strength steel columns at elevated temperatures.” Ph.D. thesis, University of Hong Kong, Hong Kong.
Chen, J., and Young, B. (2006). “Corner properties of cold-formed steel sections at elevated temperatures.” Thin-Walled Structures, 44(2), 216–223.
Chen, J., and Young, B. (2007). “Experimental investigation of cold-formed steel material at elevated temperatures.” Thin-Walled Structures, 45(1), 96–110.
Chen, W., and Ye, J. H. (2012). “Mechanical properties of G550 cold-formed steel under transient and steady state conditions.” J. Constr. Steel Res., 73, 1–11.
European Committee for Standardization (CEN). (2001). “Eurocode 3: Design of steel structures—Part 1-2: General—Structural fire design.” Brussels, Belgium.
Feng, W., Wang, Y. C., and Davies, J. M. (2003). “Structural behavior of cold-formed thin-walled short steel channel columns at elevated temperatures. Part 1: Experiments.” Thin-Walled Structures, 41(6), 543–570.
Lee, J. H., Mahendran, M., and Makelainen, P. (2003). “Prediction of mechanical properties of light gauge steels at elevated temperatures.” J. Constr. Steel Res., 59(12), 1517–1532.
Outinen, J. (1999). “Mechanical properties of structural steel at elevated temperatures.” Licentiate thesis, Helsinki University of Technology, Helsinki, Finland.
Outinen, J., Kesti, J., and Makelainen, P. (1997). “Fire design model for structural steel S355 based upon transient state tensile test results.” J. Constr. Steel Res., 42(3), 161–169.
Qu, L., Li, H., Wang, Y., Zhang, H., Bao, Y. (2008a). “Material properties of Q345 (16 Mn) steel under loading and constant temperature.” China Civ. Eng. J., 41(7), 33–40 (in Chinese).
Qu, L., Li, H., Wang, Y., Zhang, H., Bao, Y. (2008b). “Strain-temperature-stress material model of Q345 (16 Mn) steel under elevated temperature and constant loading.” China Civ. Eng. J., 41(7), 41–47 (in Chinese).
Ramberg, W., and Osgood, W. R. (1943). “Description of stress-strain curves by three parameters.”, Washington, DC.
Ranawaka, T. (2006). “Distortional buckling behavior of cold-formed steel compression members at elevated temperatures.” Ph.D. thesis, Queensland University of Technology, Brisbane, Australia.
Ranawaka, T., and Manhendran, M. (2009). “Experimental study of the mechanical properties of light gauge cold-formed steels at elevated temperatures.” Fire Saf. J., 44(2), 219–229.
Standards Australia (AS). (1979). “Methods for the tensile testing of metals at elevated temperatures.” AS 2291-1979, Sydney, Australia.
Standards Australia (AS). (1998). “Steel structures.” AS 4100-1998, Sydney, Australia.
Standards Australia (AS). (2007). “Metallic materials–Tensile testing at ambient temperature.” AS 1391-2007, Sydney, Australia.
Yu, W. W., and LaBoube, R. A. (2000). Cold-formed steel design, 3rd Ed., Wiley, New York.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 25 • Issue 8 • August 2013
Pages: 947 - 957
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jun 16, 2011
Accepted: Jul 26, 2012
Published online: Aug 24, 2012
Discussion open until: Jan 24, 2013
Published in print: Aug 1, 2013
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