A Numerical Investigation on Restrained High Strength Q460 Steel Beams Including Creep Effect
Tóm tắt
Most of previous studies on fire resistance of restrained steel beams neglected creep effect due to lack of suitable creep model. This paper presents a finite element model (FEM) for accessing the fire resistance of restrained high strength Q460 steel beams by taking high temperature Norton creep model of steel into consideration. The validation of the established model is verified by comparing the axial force and deflection of restrained beams obtained by finite element analysis with test results. In order to explore the creep effect on fire response of restrained Q460 steel beams, the thermal axial force and deflection of the beams are also analyzed excluding creep effect. Results from comparison infer that creep plays a crucial role in fire response of restrained steel beam and neglecting the effect of creep may lead to unsafe design. A set of parametric studies are accomplished by using the calibrated FEM to evaluate the governed factors influencing fire response of restrained Q460 steel beams. The parametric studies indicate that load level, rotational restraint stiffness, span–depth ratio, heating rate and temperature distribution pattern are key factors in determining fire resistance of restrained Q460 steel beam. A simplified design approach to determine the moment capacity of restrained Q460 steel beams is proposed based on the parametric studies by considering creep effect.
Tài liệu tham khảo
China Engineering Construction Standardization Association. (2006). CECS200:2006, Chinese technical code for fire safety of steel structure in buildings. Beijing: China Plan Press. (in Chinese).
Dwaikat, M. (2010). Response of restrained steel beams subjected to fire induced thermal gradients. Ph.D. dissertation. East Lansing: Michigan State University.
European Committee for Standardization. (2005). ENV1993-1-2: Eurocode3: Design of steel structures, Part 1.2: Structural fire design. Brussels, Belgium.
Field, B. A., & Field, R. J. (1989). Elevated temperature deformation of structural steel. National Institute of Standards and Technology. NISTIR 88-3899.
Guo, S. X., & Li, G. Q. (2008). Analysis of restrained steel beams subjected to heating and cooling part II: Validation and parametric studies. Steel and Composite Structure, 8(1), 19–34.
Harmathy, T. Z. (1967). A comprehensive creep model. Journal of Basic Engineering, 89(3), 496–502.
Kodur, V. K., & Aziz, E. M. (2015). Effect of temperature on creep in ASTM A572 high-strength low-alloy steels. Materials and Structures, 48(6), 1669–1677.
Kodur, V. K. R., & Dwaikat, M. M. S. (2009). Response of steel beam-columns exposed to fire. Engineering Structures, 31, 369–379.
Kodur, V. K. R., & Dwaikat, M. M. S. (2010). Effect of high temperature creep on the fire response of restrained steel beams. Materials and Structures, 43, 1327–1341.
Kodur, V. K. R., Dwaikat, M. M. S., & Fike, R. (2010). High-temperature properties of steel for fire resistance modeling of structures. Journal of Materials in Civil Engineering, 22(5), 423–434.
Laím, L., & Rodrigues, J. P. C. (2016). Experimental and numerical study on the fire response of cold-formed steel beams with elastically restrained thermal elongation. Journal of Structural Fire Engineering, 7(4), 388–402.
Li, G. Q., & Guo, S. X. (2008a). Analysis of restrained steel beams subjected to heating and cooling part I: Theory. Steel and Composite Structure, 8(1), 1–18.
Li, G. Q., & Guo, S. X. (2008b). Experiment on restrained steel beams subjected to heating and cooling. Journal of Constructional Steel Research, 64(3), 268–274.
Li, G. Q., & Zhang, C. (2012). Creep effect on buckling of axially restrained steel columns in real fires. Journal of Constructional Steel Research, 71, 182–188.
Liu, T. C. H., Fahad, M. K., & Davies, J. M. (2002). Experimental investigation of behavior of axially restrained steel beams in fire. Journal of Constructional Steel Research, 58(9), 1211–1230.
Luecke, W. E., McColskey, J. D., McCowan, C. N., et al. (2005). Federal building and fire safety investigation of the World Trade Center disaster: Mechanical properties of structural steels. Gaithersburg: National Institute of Standards and Technology.
Poh, K. W. (2001). Stress–strain–temperature relationship for structural steel. Journal of Materials in Civil Engineering, 13(5), 371–379.
Tan, K. H., & Huang, Z. K. (2002). Visco-elasto-plastic analysis of steel frames in fire. Journal of Structural Engineering, 128(1), 105–114.
Wang, W. Y., Liu, B., & Kodur, V. K. R. (2013). Effect of temperature on strength and elastic modulus of high-strength steel. Journal of Materials in Civil Engineering, 25(2), 174–182.
Wang, W. Y., Yan, S. H., & Kodur, V. K. R. (2016). Temperature induced creep in low-alloy structural Q345 steel. Journal of Materials in Civil Engineering. https://doi.org/10.1061/(ASCE)MT.1943-5533.0001519.
Wang, W. Y., Yan, S. H., & Liu, J. P. (2017). Studies on temperature induced creep in high strength Q460 steel. Materials and Structures, 50, 68.