Hidden Toe Welds in RHS-to-RHS Overlapped K-Connections
Publication: Journal of Structural Engineering
Volume 149, Issue 3
Abstract
The effects of hidden toe welds on the static behavior and strength of rectangular hollow sections to rectangular hollow sections (RHS-to-RHS) overlapped K-connections is investigated. Five full-scale welded specimens with a high overlap ratio were fabricated and tested under quasistatic loading in a universal testing machine, with the existence of hidden toe welds and branch loading condition varied. The experimental results were used to validate corresponding numerical models, and a parametric study was performed thereafter. The experimental and numerical results indicate that the overlapped K-connection capacity is affected by the presence of a hidden toe weld and the branch load case but remains within a reasonable range of the capacity predicted by certain codes and guides. Considering all the branch load cases studied, the hidden toe in a partially overlapped K-connection can be left unwelded, while some modifications are suggested to current design recommendations to account for this. A new method for calculating the branch local failure limit state is proposed, which can be used to accurately predict the capacity of overlapped RHS K-connections, without considering hidden toe welds in partially overlapped K-connections.
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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
Financial support for this project was provided by the Canadian Institute of Steel Construction (CISC), the American Institute of Steel Construction (AISC), the Steel Tube Institute (STI), the American Iron and Steel Institute (AISI), and the Natural Sciences and Engineering Research Council of Canada (NSERC). Atlas Tube (Harrow, Ontario, Canada) donated hollow structural sections for the laboratory test specimens.
References
AISC. 2022. Specification for structural steel buildings. ANSI/AISC 360-22. Chicago: AISC.
ASCE. 2016. Minimum design loads and associated criteria for buildings and other structures. ASCE/SEI 7-16. Reston, VA: ASCE.
ASTM. 2021. Standard test methods for tension testing of metallic materials. ASTM E8/E8M-21. West Conshohocken, PA: ASTM.
Bu, X.-D., and J. A. Packer. 2020. “Chord end distance effect on RHS connections.” J. Constr. Steel Res. 168 (May): 150592. https://doi.org/10.1016/j.jcsr.2020.105992.
Bu, X.-D., and J. A. Packer. 2022. “RHS-to-RHS zero-gap K-connections.” J. Struct. Eng. 148 (6): 04022055. https://doi.org/10.1061/(ASCE)ST.1943-541X.0003343.
Bu, X.-D., F. Wei, and J. A. Packer. 2021. “Laterally offset RHS X-connections.” J. Struct. Eng. 147 (1): 04020286. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002864.
Callister, W. D. 2007. Material science and engineering: An introduction. 7th ed. Hoboken, NJ: Wiley.
Caravaggio, A. G. 1988. “Tests on steel roof joints for Toronto Skydome.” MASc thesis, Dept. of Civil and Mineral Engineering, Univ. of Toronto.
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.
CEN (European Committee for Standardization). 2006. Eurocode 3: Design of steel structures—Part 1-5: Plated structural elements. EN 1993-1-5:2006. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2020. Eurocode 3: Design of steel structures—Part 1-14: Design assisted by finite element analysis. EN 1993-1-14:2020. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2021. Eurocode 3: Design of steel structures—Part 1-8: Design of joints. prEN 1993-1-8:2021. Brussels, Belgium: CEN.
Chen, Y., D. K. Liu, and J. Wardenier. 2005. “Design recommendations for RHS-K joints with 100% overlap.” In Vol. IV of Proc., 15th Int. Symp. on Offshore and Polar Engineering, 300–307. Cupertino, CA: ISOPE.
CSA (Canadian Standards Association). 2018. General requirements for rolled or welded structural quality steel/Structural quality steel. CSA G40.20-13/G40.21-13(R2018). Toronto: CSA.
CSA (Canadian Standards Association). 2019. Design of steel structures. CSA S16:19. Toronto: CSA.
Davies, G., and P. Crockett. 1994. “Effect of the hidden weld on RHS partial overlap K joint capacity.” In Proc., 6th Int. Symp. on Tubular Structures, 573–579. Rotterdam, Netherlands: A.A. Balkema.
Fisher, J. W., T. V. Galambos, G. L. Kulak, and M. K. Ravindra. 1978. “Load and resistance factor design criteria for connectors.” J. Struct. Div. 104 (9): 1427–1441. https://doi.org/10.1061/JSDEAG.0004986.
IIW (International Institute of Welding). 2012. Static design procedure for welded hollow section joints—Predominantly statically loaded. 3rd ed. Genoa, Italy: IIW.
ISO (International Organization for Standardization). 2013. Static design procedure for welded hollow section joints—Recommendations. ISO 14346. Geneva: ISO.
Kožich, M., P. Jehlička, F. Wald, X.-D. Bu, J. A. Packer, and J. Kabeláč. 2019. “Towards establishing a design resistance for hollow section joints.” In Proc., 17th Int. Symp. on Tubular Structures, 643–650. Singapore: Research Publishing.
Kožich, M., F. Wald, X.-D. Bu, and J. A. Packer. 2022. “The strain limit state criterion for hollow section joints.” Supplement, Steel Constr. 15 (S1): 2–9. https://doi.org/10.1002/stco.202100030.
Ling, Y. 1996. “Uniaxial true stress-strain after necking.” AMP J. Tech. 5 (1): 37–48. https://doi.org/10.1680/iicep.1982.1704.
Liu, D. K., Y. Chen, and J. Wardenier. 2005. “Design recommendations for RHS-K joints with 50% overlap.” In Vol. IV of Proc., 15th Int. Symp. on Offshore and Polar Engineering, 308–315. Cupertino, CA: ISOPE.
Lu, L. H., G. D. de Winkel, Y. Yu, and J. Wardenier. 1994. “Deformation limit for the ultimate strength of hollow section joints.” In Proc., 6th Int. Symp. on Tubular Structures, 341–348. Rotterdam, Netherlands: A.A. Balkema.
Packer, J. A., and G. Davies. 1982. “Ultimate strength of overlapped joints in rectangular hollow section trusses.” Proc. Inst. Civ. Eng. 73 (2): 329–350. https://doi.org/10.1680/iicep.1982.1704.
Packer, J. A., and J. E. Henderson. 1997. Hollow structural section connections and trusses—A design guide. 2nd ed. Toronto: Canadian Institute of Steel Construction.
Packer, J. A., D. Sherman, and M. Lecce. 2010. Hollow structural section connections: AISC design guide no. 24. 1st ed. Chicago: AISC.
Packer, J. A., J. Wardenier, X.-L. Zhao, G. J. van der Vegte, and Y. Kurobane. 2009. Design guide for rectangular hollow section (RHS) joints under predominantly static loading: CIDECT design guide no. 3. 2nd ed. Geneva: Comité International pour le Développement et l’Étude de la Construction Tubulaire.
Ravindra, M. K., and T. V. Galambos. 1978. “Load and resistance factor design for steel.” J. Struct. Div. 104 (9): 1337–1353. https://doi.org/10.1061/JSDEAG.0004981.
Wald, F., et al. 2017. Benchmark cases for advanced design of structural steel connections. 2nd ed. Prague, Czechia: Czech Technical Univ. in Prague.
Wardenier, J., and C. H. M. de Koning. 1976. Investigation into the static strength of welded lattice girder joints in structural hollow sections. Part 1: Rectangular hollow sections. Delft, Netherlands: Delft Univ. of Technology.
Wardenier, J., X. Lan, and J. A. Packer. 2021. Re-analysis of full-width RHS T- and X-joints under brace axial tension and brace in-plane bending. Delft, Netherlands: Delft Univ. of Technology.
Wardenier, J., J. A. Packer, R. Puthli, and F. Bijlaard. 2016. “Re-evaluation of the shear criterion for RHS overlap joints.” Steel Constr. 9 (4): 339–348. https://doi.org/10.1002/stco.201610039.
Wardenier, J., and J. W. B. Stark. 1978. The static strength of welded lattice girder joints in structural hollow sections. Delft, Netherlands: Delft Univ. of Technology.
Wardenier, J., G. J. van der Vegte, J. A. Packer, and X.-L. Zhao. 2010. “Background of the new RHS joint strength equations in the IIW (2009) recommendations.” In Proc., 13th Int. Symp. on Tubular Structures, 403–412. Boca Raton, FL: CRC Press.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 149 • Issue 3 • March 2023
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Jun 24, 2022
Accepted: Oct 28, 2022
Published online: Dec 26, 2022
Published in print: Mar 1, 2023
Discussion open until: May 26, 2023
ASCE Technical Topics:
- Analysis (by type)
- Connections (structural)
- Construction engineering
- Construction methods
- Design (by type)
- Engineering fundamentals
- Finite element method
- Foundation design
- Foundations
- Geotechnical engineering
- Load bearing capacity
- Load factors
- Load tests
- Methodology (by type)
- Models (by type)
- Numerical analysis
- Numerical methods
- Numerical models
- Structural design
- Structural engineering
- Structural members
- Structural systems
- Tests (by type)
- Welding
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Cited by
- Xiao Ding Bu, Vartkes Davidian, Jeffrey A. Packer, Wei Li, RHS Cross-Connections with Fully Offset Branches in Tension, Journal of Structural Engineering, 10.1061/JSENDH.STENG-12762, 150, 8, (2024).