Full-Scale Experiments of Cyclically Loaded Welded Moment Connections with Highly Dissipative Panel Zones and Simplified Weld Details
Publication: Journal of Structural Engineering
Volume 149, Issue 12
Abstract
This paper presents the experimental results of two welded unreinforced flange-welded web (WUF-W) beam-to-column connections that defy the current design paradigm of prequalified welded connections. The proposed WUF-W connections feature customized beveled backing bars that are intentionally left in place after the completion of the beam flange-to-column face complete joint penetration welds. The connection design aims at a stable hysteretic response by exploiting the beneficial aspects of appreciable panel zone shear yielding (i.e., inelastic shear distortions of at least , where is the panel zone shear distortion at yield), by considering a shear strength-to-demand ratio of 0.8. To prevent divot fracture in the column, minimum through-thickness toughness requirements were imposed for the steel column material. The experimental results suggest that the proposed WUF-W connections achieve a stable hysteretic response up until lateral drift demands of at least 7% rad, while a non-softening response was assured up to 9% rad. The beveled backing bars minimize the associated fracture potential near the beam web centerline, which is a primary concern in prequalified field welded moment connections when conventional weld backing bars are employed. The tests suggest that, under a symmetric cyclic loading protocol, local buckling near the steel beams is prevented up until a lateral drift demand of 6% rad, which is an important finding from structural repairability and stability standpoints. The ultimate failure modes of the welded connections, which are attributable to ductile crack initiation and propagation, are consistent regardless of the employed lateral loading histories, which involved standard symmetric cyclic and collapse-consistent loading protocols. The implications for the seismic design of steel moment resisting frames (MRFs) and the limitations of the present work are discussed.
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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
This study is based on work supported by a Nippon Steel Corporation collaborative grant as well as an EPFL internal grant. The financial support is gratefully acknowledged. The authors would like to sincerely thank Techno Steel Daishin, which fabricated the test specimens, Mr. Kenta Yoshiba, who performed the connection welding, and Mr. Shun Ri who performed the ultrasonic testing. The authors would also like to sincerely thank the personnel of the Hasaki Laboratory of Nippon Steel Corporation as well as Dr. Yusuke Suzuki (Senior Manager of Nippon Steel Corporation) for several insightful discussions during the project. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the sponsors.
References
AIJ (Architectural Institute of Japan). 2018a. Standard for the ultrasonic inspection of weld defects in steel structures. [In Japanese.] Tokyo: AIJ.
AIJ (Architectural Institute of Japan). 2018b. Technical recommendations for steel construction for buildings Part1: Guide to steel-rib fabrications. [In Japanese.] Tokyo: AIJ.
AISC. 2016a. Prequalified connections for special and intermediate steel moment frames for seismic applications. ANSI/AISC 358-16. Chicago: AISC.
AISC. 2016b. Seismic provisions for structural steel buildings. ANSI/AISC 341-16. Chicago: AISC.
AISC. 2016c. Specification for structural steel buildings. ANSI/AISC 360-16. Chicago: AISC.
Alavi, B., and H. Krawinkler. 2004. “Behavior of moment-resisting frame structures subjected to near-fault ground motions.” Earthquake Eng. Struct. Dyn. 33 (6): 687–706. https://doi.org/10.1002/eqe.369.
ASTM. 2016. Standard test methods for tension testing of metallic materials. ASTM E8/E8M-16a. West Conshohocken, PA: ASTM.
ASTM. 2018. Standard specification for through-thickness tension testing of steel plates for special applications. A770/A770M-03. West Conshohocken, PA: ASTM.
ASTM. 2021. Standard test methods and definitions for mechanical testing of steel products. ASTM A370-21. West Conshohocken, PA: ASTM.
AWS (American Welding Society). 2010. Structural welding code—Steel. ANSI/AWS D1.1:2010. Miami: AWS.
AWS (American Welding Society). 2016. Structural welding code-seismic supplement. AWS D1.8/D1.8M:2016. Miami: AWS.
Bouchard, S., and G. Axmann. 2000. “ASTM A913 grades 50 and 65: Steels for seismic applications.” In Proc., 3rd Int. Conf. on Behavior of Steel Structures in Seismic Areas (STESSA), 11–17. Montreal: CRC Press.
CEN (European Committee for Standardization). 2004. Eurocode 3: Design of steel structures—Part 10: Material toughness and through-thickness properties. EN 1993-1-10. Brussels, Belgium: CEN.
Chi, B., and C.-M. Uang. 2002. “Cyclic response and design recommendations of reduced beam section moment connections with deep columns.” J. Struct. Eng. 128 (4): 464–473. https://doi.org/10.1061/(ASCE)0733-9445(2002)128:4(464).
Chi, W. M., G. G. Deierlein, and A. Ingraffea. 1997. Finite element fracture mechanics investigation of welded beam-column connections. Sacramento, CA: SAC Joint Venture.
Chi, W.-M., G. G. Deierlein, and A. Ingraffea. 2000. “Fracture toughness demands in welded beam-column moment connections.” J. Struct. Eng. 126 (1): 88–97. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:1(88).
El Jisr, H., A. Elkady, and D. G. Lignos. 2019. “Composite steel beam database for seismic design and performance assessment of composite-steel moment-resisting frame systems.” Bull. Earthquake Eng. 17 (6): 3015–3039. https://doi.org/10.1007/s10518-019-00564-w.
Elkady, A., and D. G. Lignos. 2015. “Effect of gravity framing on the overstrength and collapse capacity of steel frame buildings with perimeter special moment frames.” Earthquake Eng. Struct. Dyn. 44 (8): 1289–1307. https://doi.org/10.1002/eqe.2519.
El-Tawil, S. 2000. “Panel zone yielding in steel moment connections.” Eng. J. 37 (3): 120–131.
El-Tawil, S., E. Vidarsson, T. Mikesell, and S. K. Kunnath. 1999. “Inelastic behavior and design of steel panel zones.” J. Struct. Eng. 125 (2): 183–193. https://doi.org/10.1061/(ASCE)0733-9445(1999)125:2(183).
Engelhardt, M. D., M. J. Venti, G. T. Fry, S. L. Jones, and S. D. Holliday. 2000. Behavior and design of radius cut reduced beam section connections. Sacramento, CA: SAC Joint Venture.
FEMA. 2000. State of the art report on connection performance. Washington, DC: FEMA.
FEMA. 2009. Effects of strength and stiffness degradation on seismic response. Washington, DC: FEMA.
FEMA. 2012. Seismic performance assessment of buildings. Rep. No. FEMA-P-58-1. Washington, DC: FEMA.
Fujisawa, K., Y. Ichinohe, M. Sugimoto, and M. Sonoda. 2013. “Statistical study on mechanical properties and chemical compositions of SN Steels.” In Proc., Summary of Technical Papers of Annual Meeting, 699–700. Tokyo: Architectural Institute of Japan.
Gupta, A., and H. Krawinkler. 2000. “Dynamic P-delta effects for flexible inelastic steel structures.” J. Struct. Eng. 126 (1): 145–154. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:1(145).
Hajjar, J. F., R. T. Leon, M. A. Gustafson, and C. K. Shield. 1998. “Seismic response of composite moment-resisting connections. II: Behavior.” J. Struct. Eng. 124 (8): 877–885. https://doi.org/10.1061/(ASCE)0733-9445(1998)124:8(877).
Han, S. W., G. U. Kwon, and K. H. Moon. 2007. “Cyclic behaviour of post-Northridge WUF-B connections.” J. Constr. Steel Res. 63 (3): 365–374. https://doi.org/10.1016/j.jcsr.2006.05.003.
Ibarra, L. F., and H. Krawinkler. 2005. Global collapse of frame structures under seismic excitations. Stanford, CA: The John A. Blume Earthquake Engineering Research Center, Dept. of Civil Engineering, Stanford Univ.
Ibarra, L. F., R. A. Medina, and H. Krawinkler. 2005. “Hysteretic models that incorporate strength and stiffness deterioration.” Earthquake Eng. Struct. Dyn. 34 (12): 1489–1511. https://doi.org/10.1002/eqe.495.
Kanvinde, A. M. 2017. “Predicting fracture in civil engineering steel structures: State of the art.” J. Struct. Eng. 143 (3): 03116001. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001704.
Kim, S.-Y., and C.-H. Lee. 2017. “Seismic retrofit of welded steel moment connections with highly composite floor slabs.” J. Constr. Steel Res. 139 (Dec): 62–68. https://doi.org/10.1016/j.jcsr.2017.09.010.
Krawinkler, H. 1995. “Earthquake design and performance of steel structures.” In Proc., Pacific Conf. on Earthquake Engineering, PCEE 95. Richmond, VIC, Australia: Australian Earthquake Engineering Society.
Krawinkler, H. 1996. “Cyclic loading histories for seismic experimentation on structural components.” Earthquake Spectra 12 (1): 1–12. https://doi.org/10.1193/1.1585865.
Krawinkler, H. 2009. “Loading histories for cyclic tests in support of performance assessment of structural components.” In Proc., 3rd Int. Conf. on Advances in Experimental Structural Engineering. San Francisco: Pacific Earthquake Engineering Research Center.
Krawinkler, H., G. Akshay, R. Medina, and M. Luco. 2000. Development of loading histories for testing of steel beam-to-column assemblies. Stanford, CA: Dept. of Civil and Environmental Engineering, Stanford Univ.
Krawinkler, H., V. V. Bertero, and E. P. Popov. 1971. Inelastic behavior of steel beam-to-column subassemblages. Berkeley, CA: Univ. of California.
Krawinkler, H., and G. G. Deierlein. 2013. “Chapter 1: Challenges towards achieving earthquake resilience through performance-based earthquake engineering.” In Performance-based seismic engineering: Vision for an earthquake resilient society, edited by M. Fischinger. New York: Springer.
Lee, D., S. C. Cotton, J. Hajjar, R. J. Dexter, and Y. Ye. 2005a. “Cyclic behavior of steel moment-resisting connections reinforced by alternative column stiffener details I. Connection performance and continuity plate detailing.” Eng. J. 42 (4): 189–214.
Lee, D., S. C. Cotton, J. F. Hajjar, R. J. Dexter, and Y. Ye. 2005b. “Cyclic behavior of steel moment-resisting connections reinforced by alternative column stiffener details II. Panel zone behavior and doubler plate detailing.” Eng. J. 42 (4): 215–238.
Leon, R. T., J. F. Hajjar, and M. A. Gustafson. 1998. “Seismic response of composite moment-resisting connections. I: Performance.” J. Struct. Eng. 124 (8): 868–876. https://doi.org/10.1061/(ASCE)0733-9445(1998)124:8(868).
Lignos, D. G., H. Krawinkler, and A. S. Whittaker. 2011. “Prediction and validation of sidesway collapse of two scale models of a 4-story steel moment frame.” Earthquake Eng. Struct. Dyn. 40 (7): 807–825. https://doi.org/10.1002/eqe.1061.
Lin, K. C., K. C. Tsai, S. L. Kong, and S. H. Hsieh. 2000. “Effects of panel zone deformations on cyclic performance of welded moment connections.” In Proc., 12th World Conf. on Earthquake Engineering (WCEE). Auckland, New Zealand: New Zealand National Society for Earthquake Engineering.
Lu, L. W., J. M. Ricles, C. Mao, and J. W. Fisher. 2000. “Critical issues in achieving ductile behaviour of welded moment connections.” J. Constr. Steel Res. 55 (1–3): 325–341. https://doi.org/10.1016/S0143-974X(99)00092-9.
Mahin, S., J. Malley, and R. Hamburger. 2002. “Overview of the FEMA/SAC program for reduction of earthquake hazards in steel moment frame structures.” J. Constr. Steel Res. 58 (5–8): 511–528. https://doi.org/10.1016/S0143-974X(01)00088-8.
Maison, B. F., and M. S. Speicher. 2016. “Loading protocols for ASCE 41 backbone curves.” Earthquake Spectra 32 (4): 2513–2532. https://doi.org/10.1193/010816EQS007EP.
Malley, J. O. 1998. “SAC steel project: Summary of Phase 1 testing investigation results.” Eng. Struct. 20 (4–6): 300–309. https://doi.org/10.1016/S0141-0296(97)00033-3.
Mao, C., J. Ricles, L. W. Lu, and J. Fisher. 2001. “Effect of local details on ductility of welded moment connections.” J. Struct. Eng. 127 (9): 1036–1044. https://doi.org/10.1061/(ASCE)0733-9445(2001)127:9(1036).
Miller, D. K. 2017. Design guide 21: Welded connections—A primer for engineers. 2nd ed. Chicago: American Institute of Steel Construction.
NIST. 2010. Evaluation of the FEMA P-695 methodology for quantification of building seismic performance factors. Gaithersburg, MD: NIST.
Paret, T. F. 2000. “The W1 Issue. II: UT reliability for inspection of T-joints with backing.” J. Struct. Eng. 126 (1): 19–23. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:1(19).
Popov, E. P., T.-S. Yang, and S.-P. Chang. 1998. “Design of steel MRF connections before and after 1994 Northridge earthquake.” Eng. Struct. 20 (12): 1030–1038. https://doi.org/10.1016/S0141-0296(97)00200-9.
Rahiminia, F., and H. Namba. 2013. “Joint panel in steel moment connections, part 1: Experimental tests results.” J. Constr. Steel Res. 89 (Oct): 272–283. https://doi.org/10.1016/j.jcsr.2013.07.002.
Reynolds, M., and C.-M. Uang. 2022. “Economical weld details and design for continuity and doubler plates in steel special moment frames.” J. Struct. Eng. 148 (1): 04021246. https://doi.org/10.1061/(ASCE)ST.1943-541X.0003203.
Ricles, J. M., J. W. Fisher, L.-W. Lu, and E. J. Kaufmann. 2002a. “Development of improved welded moment connections for earthquake-resistant design.” J. Constr. Steel Res. 58 (5–8): 565–604. https://doi.org/10.1016/S0143-974X(01)00095-5.
Ricles, J. M., C. Mao, L. W. Lu, and J. W. Fisher. 2003. “Ductile details for welded unreinforced moment connections subject to inelastic cyclic loading.” Eng. Struct. 25 (5): 667–680. https://doi.org/10.1016/S0141-0296(02)00176-1.
Ricles, J. M., C. Mao, L.-W. Lu, and J. W. Fisher. 2000. Development and evaluation of improved details for ductile welded unreinforced flange connections. Sacramento, CA: SAC Joint Venture.
Ricles, J. M., C. Mao, L.-W. Lu, and J. W. Fisher. 2002b. “Inelastic cyclic testing of welded unreinforced moment connections.” J. Struct. Eng. 128 (4): 429–440. https://doi.org/10.1061/(ASCE)0733-9445(2002)128:4(429).
Ricles, J. M., X. Zhang, L.-W. Lu, and J. W. Fisher. 2004. Development of seismic guidelines for deep-column steel moment connections. Bethlehem, PA: Lehigh Univ.
Shaw, S. M., K. Stillmaker, and A. M. Kanvinde. 2015. “Seismic response of partial-joint-penetration welded column splices in moment-resisting frames.” Eng. J. 52 (2): 87–108.
Shin, S. 2017. “Experimental and analytical investigation of panel zone behavior in steel moment frames.” Ph.D. dissertation, Dept. of Civil, Architectural and Environmental Engineering, Univ. of Texas at Austin.
Skiadopoulos, A. 2022. “Welded moment connections with highly dissipative panel zones for enhanced seismic performance of steel moment frames.” Ph.D. thesis, Dept. of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne.
Skiadopoulos, A., A. Elkady, and D. G. Lignos. 2021. “Proposed panel zone model for seismic design of steel moment-resisting frames.” J. Struct. Eng. 147 (4): 04021006. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002935.
Skiadopoulos, A., and D. G. Lignos. 2021. “Development of inelastic panel zone database.” J. Struct. Eng. 147 (4): 04721001. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002957.
Skiadopoulos, A., and D. G. Lignos. 2022a. “Proposed backing bar detail in welded beam-to-column connections for seismic applications.” J. Struct. Eng. 148 (8): 04022102. https://doi.org/10.1061/(ASCE)ST.1943-541X.0003374.
Skiadopoulos, A., and D. G. Lignos. 2022b. “Seismic demands of steel moment resisting frames with inelastic beam-to-column web panel zones.” Earthquake Eng. Struct. Dyn. 51 (7): 1591–1609. https://doi.org/10.1002/eqe.3629.
Stillmaker, K., A. Kanvinde, and C. Galasso. 2016. “Fracture mechanics-based design of column splices with partial joint penetration welds.” J. Struct. Eng. 142 (2): 04015115. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001380.
Stojadinović, B., S. C. Goel, K.-H. Lee, A. G. Margarian, and J.-H. Choi. 2000. “Parametric tests on unreinforced steel moment connections.” J. Struct. Eng. 126 (1): 40–49. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:1(40).
Suzuki, Y., and D. G. Lignos. 2020. “Development of collapse-consistent loading protocols for experimental testing of steel columns.” Earthquake Eng. Struct. Dyn. 49 (2): 114–131. https://doi.org/10.1002/eqe.3225.
Suzuki, Y., and D. G. Lignos. 2021. “Experimental evaluation of steel columns under seismic hazard-consistent collapse loading protocols.” J. Struct. Eng. 147 (4): 04021020. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002963.
Tremblay, R., P. Timler, M. Bruneau, and A. Filiatrault. 1995. “Performance of steel structures during the 1994 Northridge earthquake.” Can. J. Civ. Eng. 22 (2): 338–360. https://doi.org/10.1139/l95-046.
Uang, C.-M., and M. Bruneau. 2018. “State-of-the-art review on seismic design of steel structures.” J. Struct. Eng. 144 (4): 03118002. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001973.
Whittaker, A., A. Gilani, and V. Bertero. 1998. “Evaluation of pre-Northridge steel moment-resisting frame joints.” Struct. Des. Tall Build. 7 (4): 263–283. https://doi.org/10.1002/(SICI)1099-1794(199812)7:4%3C263::AID-TAL118%3E3.0.CO;2-B.
Zhang, X., and J. M. Ricles. 2006. “Experimental evaluation of reduced beam section connections to deep columns.” J. Struct. Eng. 132 (3): 346–357. https://doi.org/10.1061/(ASCE)0733-9445(2006)132:3(346).
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 149 • Issue 12 • December 2023
Copyright
© 2023 American Society of Civil Engineers.
History
Received: Oct 4, 2022
Accepted: Feb 14, 2023
Published online: Sep 23, 2023
Published in print: Dec 1, 2023
Discussion open until: Feb 23, 2024
ASCE Technical Topics:
- Beams
- Connections (structural)
- Continuum mechanics
- Cracking
- Cyclic loads
- Dynamic loads
- Dynamics (solid mechanics)
- Engineering mechanics
- Fracture mechanics
- Material mechanics
- Material properties
- Materials engineering
- Moment (mechanics)
- Panels (structural)
- Shear strength
- Solid mechanics
- Statics (mechanics)
- Steel beams
- Strength of materials
- Structural dynamics
- Structural engineering
- Structural members
- Structural systems
- Welded connections
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