A parametric study on OPB fire response of steel CHS T-joints

Document Type : Research Article

Authors

1 Ph.D student, Civil Engineering Department, K.N.Toosi University of Technology, Tehran, Iran

2 Professor of Civil Engineering Department, K.N.Toosi University of Technology

3 Department of Civil Engineering, Parand Branch, Islamic Azad University, Parand, Iran

4 Ph.D student, Civil Engineering Department, K.N.Toosi University of Technology

5 Master of Structural Laboratory, Civil Engineering Department, K.N.Toosi University of Technology

Abstract

The behavior of steel circular hollow section (CHS) T-joints under combined fire load and out-of-plane bending (OPB) is investigated. A review of the literature indicates that the subject has not been previously considered by researchers. The authors carried out the first laboratory experimental study on OPB behavior of simple steel tubular T-joints under standard fire. The results of an experimental and numerical study performed on three small-scale steel tubular T-joint specimens are reported. One specimen was tested at ambient temperature under quasi-static incremental OPB moment in the brace and the other two specimens were tested under OPB moment plus exposure to ISO-834 standard fire. In order to have a deeper insight into the strength and failure mechanism of steel tubular T-joints under fire, their OPB behavior was also studied using coupled mechanical-thermal finite element modeling. The numerical model was validated against the experimental results and reasonable agreements were achieved. A parametric study was then performed on the OPB fire behavior of full-scale steel tubular T-joints. The results showed that the superimposed OPB ratio in the brace and the diameter ratio parameter had more pronounced effects on the fire response of the joint as compared to other geometric and loading parameters. Increasing the diameter ratio parameter from 0.2 to 1, reduced the joints residual rotation by 56 % and increased the critical temperature by 23 %. By increasing the OPB ratio from 0.2 to 1, the residual rotation increased by 245 % and the critical temperature decreased by 37%.

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[1] Z.J. Jin M, Chang J, Liu ML, Mechanical behavior of tubular T-joint after fire, Journal of Shanghai Jiaotong University 67 (2011) 75-78.
[2] Z.J. Jin M, Chang J, Zhang D, Experimental and parametric study on the post fire behavior of tubular T-joint, Journal of Constructional Steel Research, 70 (2012) 93-100.
[3] S.Y. He SB, Zhang HY, Yang DP, Long FL, Experimental study on circular hollow section (CHS) tubular K-joints at elevated temperature, Eng Fail Anal 34 (2013) 204-216.
[4] S. He, Shao, Y., Zhang, H. and Wang, Q., Parametric study on performance of circular tubular K-joints at elevated temperature, Fire Safety Journal, 71 (2015) 174-186.
[5] S.Y.Z. He S.B., H., Evaluation on fire resistance of tubular K-joints based on critical temperature method, Journal of Constructional Steel Research, 115 (2015) 398-406.
[6] E.a.W. Ozyurt, Y.C., A numerical investigation of static resistance of welded planar steel tubular joints under in-plane and out-of-plane bending at elevated temperatures, Engineering Structures, 199 (2019) 109622.
[7] T.K. Fung TC, Nguyen MP, Structural behaviour of CHS T-joints subjected to static in-plane bending in fire condition, J Struct Eng 142 (3) (2015) 04015155.
[8] H.M. Darmian, R. Rahgozar, M. Mohammadizadeh, A.S. Daryan, K. Narmashiri. The effect of the behaviour of perforated short steel compression members and evaluation after retrofitting, Amirkabir Journal of Civil Engineering, 2021. doi:10.22060/ceej.2021.19938.7289, (in persian).
[9] Q.W. Shenggang Fan, Runmin Ding, Lianlian Jia, Hang Zhou, Experimental and numerical research on fire resistance of stainless steel tubular X-joints, J Constr Steel Res 182 (2021) 106654.
[10] H.A. Neda Azari-Dodaran, Lei Zhu & Peiyang Li. , Experimental and numerical study of the ultimate load for collar-plate-reinforced tubular K-joints at fire-induced elevated temperatures, Ships and Offshore Structures,  (2021) 1897221.
[11] S.Y. Cheng C, Jie Y, Experimental and numerical study on fire resistance of circular tubular T-joints. , 85 (2013) 24-39.
[12] Z.Y. Shao YB, Zhao HC, Yang DP., Performance of tubular T-joints at elevated temperature by considering effect of chord compressive stress. , Thin-Walled Struct 98 (2016) 533-546.
[13] H.Y. Lan X., Chan T.M. and Young, B. , Static strength of stainless steel K-and N-joints at elevated temperatures., Thin-Walled Structures 122 (2018) 501-509.
[14] A. Azari-Dodaran N., H., Structural behavior of right-angle two-planar tubular TT-joints subjected to axial loadings at fire-induced elevated temperatures, Fire Safety Journal, 108 (2019) 102849.
[15] Saberi, V., saberi, H., Panahkhah, S., Sadeghi, A., Noroozinejad Farsangi, E. Investigation of the Effect of Fire Loading on the Behavior of Connections with Beam-to-Column Bolted End Plate and T-Connection. Journal of Structural and Construction Engineering, 2021. doi: 10.22065/jsce.2021.303562.2563.
[16] ABAQUS user's manual [Computer software], in, Hibbit. Karlsson & Sorensen Inc, 2017.
[17] Esmaeili niari, S., Ghandi, E., samiee, P. Investigation of Buckling Behaviour of Cold- Formed Steel Columns with Built-up Sections Subjected to Fire. Journal of Structural and Construction Engineering, 2021: 8(7). doi:10.22065/jsce.2020.232335.2146.
[18] Yahyai, M., Rezaeian, A. Performance of Link-To-Stub Bolted Connection in Column-Tree Moment Resisting Frames under Fire Conditions. Journal of Structural and Construction Engineering, 2015: 2(3), 23-33.
[19] ISO 834, in:  Fire-Resistance Tests-Elements of Building Construction: Part 1: General Requirements, International Organization for Standardization, Geneva, Switzerland, 1999.
[20] Saberi, H., Saberi, V., Khodamoradi, N. et al. Effect of detailing on performance of steel T-connection under fire loading. J Build Rehabil, 2022: 7(1). doi:10.1007/s41024-021-00147-w.
[21] Z.M., Ahmadpour F, Mo’tamedi M, Rashnooie R. , Experimental study of fire effects on out-of-plane bending strength/ flexibility of steel tubular T-joints, Structures, 34 (2021) 2174-2188.
[22] ASTM A370, in: American Society for Testing and Materials, standard test methods and definitions for mechanical testing of steel products., West Conshohocken: ASTM, 2014.
[23] API, in: Recommended practice for planning, designing and constructing fixed offshore platforms. RP 2A, API Publishing Services. Washington, DC, 2007.
[24] AWS, in:  Structural welding code-steel, American Welding Society. AWS D1.1; 2000.
[25] H.S.A. Zeinoddini M., Fire response of externally stiffened steel I-beam-to-CHS welded connections: A numerical modelling, Journal of Constructional Steel Research 89 (2013) 42-51.
[26] Z.M. Hosseini SA., Model fire tests on a beam to leg connection in an offshore platform topside, Fire Mater J 38 (2014) 529-549.
[27] Z.M. Hosseini SA., Darian A.S., Modelling of I-shaped beam-to-tubular column connection subjected to post-fire conditions, Int J Steel Struct 14 (3) (2014) 513-528.
[28] P.J. Wang M, Chang PC, Quintiere JG., Scale modeling of compartment fires for structural fire testing. , J Fire Prot Eng, 18 (2008) 228-240.
[29] Z.N. Yura JA, Edwards IF, Ultimate capacity equations for tubular joints, in: Offshore Technology Conference, Texas, 1980.
[30] G.X. Gao F, Zhu HP, Ye Y. , Fire-resistance behavior of completely overlapped tubular joints under lap brace axial loading, J Struct Eng 144 (9) (2018) 04018137.
[31] Eurocode 3 (EC3), in:  Design of steel structures - Part 1-2: General rules -Structural fire design, European Committee for Standardization, Brussels, Belgium, 2005.
[32] Z.H. Gao F, Liu XN., Failure behavior of axially loaded tubular Y-joints under fire, Adv Struct Eng 16 (9) (2013) 1523-1533.