Analytical Strength Prediction Model for Full-Width Circular Hollow Section X-Joints
Publication: Journal of Structural Engineering
Volume 147, Issue 9
Abstract
Full-width tubular joints, consisting of chord and brace members of the same width (or diameter), have been frequently used in architectural, civil, and offshore structures owing to their higher load resistance compared with partial-width joints. In design standards, the full-width circular hollow section (CHS) joints have been treated as exhibiting chord plastification behavior similar to those of joints with lower brace-to-chord diameter ratios. However, in this study, it is found that for full-width CHS X-joints, the bearing or buckling behavior of the chord sidewall should also be considered for more accurate and consistent prediction of the joint strength. A new analytical model based on the column buckling approach, which accounts for both chord sidewall failure and chord plastification, is proposed. Further, it is shown that the proposed model could be regarded as more generic than the classical ring model that formed the analytical basis of current design standards. The proposed model is employed to derive a new design formula for CHS X-joints subjected to brace axial compression including high-strength steel. The application of the proposed design formula is limited to laterally restrained joints because the reduction in joint strength due to sidesway instability can be significant.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
The authors are grateful for and acknowledge the support of the POSCO Affiliated Research Professor Program for this study.
References
AWS (American Welding Society). 2015. Structural welding code—Steel. Miami: AWS.
Bucak, Ö., S. Herion, O. Fleischer, and H. Ehard. 2016. “Zur Abminderung der Knotentragfähigkeit von Hohlprofilknoten aus hochfesten Kreishohlprofilen.” [In German.] Stahlbau 85 (11): 747–763. https://doi.org/10.1002/stab.201610425.
CEN (European Committee for Standardization). 1997a. Cold formed welded structural sections of non-alloy and fine grain steels: Tolerances, dimensions and sectional properties. EN 10219-2. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 1997b. Hot finished structural hollow sections of non-alloy and fine grain structural steels: Tolerances, dimensions and sectional properties. EN 10210-2. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2002. Basis of structural design. EN 1990:2002. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2005. Eurocode 3: Design of steel structures—Part 1.8: Design of joints. EN 1993-1-8:2005. Brussels, Belgium: CEN.
EPR (Exxon Production Research). 1971. Experimental determination of the ultimate strength of tubular joints. Houston: EPR.
Fan, Y. 2017. “RHS-to-RHS axially loaded X-connections offset towards an open chord end.” Doctoral dissertation, Dept. of Civil and Mineral Engineering, Univ. of Toronto.
ISO. 2013. Static design procedure for welded hollow-section joints—Recommendations. ISO/FDIS 14346:2012(E). Geneva: IOS.
JISC (Japanese Industrial Standards Committee). 1972. Study of tubular joints used in marine structures. Tokyo: JISC.
Kanatani, H. 1966. Experimental study on welded tubular connections, 13–41. Kobe, Japan: Kobe Univ.
Kang, C. T., D. G. Moffat, and J. Mistry. 1998. “Strength of DT tubular joints with brace and chord compression.” J. Struct. Eng. 124 (7): 775–783. https://doi.org/10.1061/(ASCE)0733-9445(1998)124:7(775).
Kim, J.-H., C.-H. Lee, S.-H. Kim, and K.-H. Han. 2019. “Experimental and analytical study of high-strength steel RHS X-joints under axial compression.” J. Struct. Eng. 145 (12): 04019148. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002435.
Kim, S.-H., and C.-H. Lee. 2020. “Investigation of high-strength steel CHS X-joints loaded in compression including effect of chord stresses.” Eng. Struct. 205 (Feb): 110052. https://doi.org/10.1016/j.engstruct.2019.110052.
Lan, X. 2019. “Structural behaviour and design of high strength steel tubular sections and tubular joints.” Doctoral dissertation, Dept. of Civil and Environmental Engineering, Hong Kong Polytechnic Univ.
Lee, C. H., and S. H. Kim. 2018. “Structural performance of CHS X-joints fabricated from high-strength steel.” Steel Constr. 11 (4): 278–285. https://doi.org/10.1002/stco.201800021.
Lee, C. H., S. H. Kim, D. H. Chung, D. K. Kim, and J. W. Kim. 2017. “Experimental and numerical study of cold-formed high-strength steel CHS X-joints.” J. Struct. Eng. 143 (8): 04017077. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001806.
Lipp, A., and T. Ummenhofer. 2015. “Influence of tensile chord stresses on the strength of CHS X-joints—Experimental and numerical investigations.” In Proc., 15th Int. Symp. Tubular Structures, Tubular Structures XV, 379–386. Boca Raton, FL: CRC Press.
Maquoi, R., and J. Rondal. 1978. “Mise en equation des nouvelles courbes Européennes de flambement.” Constr. Mét. 15 (1): 17–30.
Noordhoek, C., and A. Verheul. 1998. Static strength of high strength steel tubular joints. Delft, Netherlands: Delft Univ. of Technology.
Qian, X. D. 2005. “Static strength of thick-walled CHS joints and global frame behavior.” Doctoral dissertation, Dept. of Civil Engineering, National Univ. of Singapore.
Simulia. 2014. Abaqus 6.14: Abaqus/CAE user’s guide. Providence, RI: Simulia.
Soh, C. K., T. K. Chan, and S. K. Yu. 2000. “Limit analysis of ultimate strength of tubular X-joints.” J. Struct. Eng. 126 (7): 790–797. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:7(790).
Togo, T. 1967. “Experimental study on mechanical behavior of tubular joints.” Doctoral dissertation, Dept. of Architectural Engineering, Osaka Univ.
Van der Vegte, G. J. 1995. “The static strength of uniplanar and multiplanar tubular T-and X-joints.” Doctoral dissertation, Dept. of Civil Engineering and Geosciences, Delft Univ. of Technology.
Van der Vegte, G. J., Y. Makino, D. K. Liu, and J. Wardenier. 2001. “The influence of chord stress on the ultimate strength of axially loaded uniplanar X-joints.” In Proc., 9th Int. Symp. on Tubular Structures, Tubular Structures IX, 165–174. Lisse, Netherlands: A.A. Balkema.
Van der Vegte, G. J., J. Wardenier, X. L. Zhao, and J. A. Packer. 2008. “Evaluation of new CHS strength formulae to design strengths.” In Proc., 12th Int. Symp. on Tubular Structures, Tubular Structures XII, 313–322. Boca Raton, FL: CRC Press.
Wardenier, J., Y. Kurobane, J. A. Packer, G. J. Van der Vegte, and X. L. Zhao. 2008. Construction with hollow steel sections—No.1: Design guide for circular hollow section (CHS) joints under predominantly static loading. 2nd ed. Geneva: CIDECT.
Weinstein, R. M., and J. A. Yura. 1986. “The effect of chord stresses on the static strength of DT tubular connections.” In Proc., Offshore Technology Conf., 5135. Houston: Offshore Technology Conference.
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Published In
Journal of Structural Engineering
Volume 147 • Issue 9 • September 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Apr 29, 2020
Accepted: Apr 2, 2021
Published online: Jul 7, 2021
Published in print: Sep 1, 2021
Discussion open until: Dec 7, 2021
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