Reassessment of the Lateral Torsional Buckling Resistance of I-Section Members: Uniform-Moment Studies
Publication: Journal of Structural Engineering
Volume 143, Issue 3
Abstract
The I-section member lateral torsional buckling (LTB) resistance equations of the unified provisions underlying the current AISC and AASHTO specifications are a fit to a large body of experimental test data. It has been observed that finite-element (FE) test simulations commonly predict smaller capacities than the AISC/AASHTO LTB equations, especially in the inelastic LTB region. One reason for this disconnect is the fact that the residual stresses and geometric imperfections are often approximated by conservative nominal values in test simulations. Another reason for the discrepancy is the common lack of consideration of inelastic effective length effects within calibrations to experimental test results. This paper recommends improvements to the current LTB resistance equations to address these shortcomings. The impact of inelastic end restraint in representative beam LTB experimental tests is illustrated through FE test simulations. In addition, extensive test simulation results are presented, based on reduced residual stresses and geometric imperfections determined in separate research, which illustrate the quality of the proposed prediction equations for I-section members of various cross section types subjected to uniform moment.
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References
AASHTO. (2015). “AASHTO LRFD bridge design specifications.” 7th Ed., Washington, DC.
Abaqus 6.12-1 [Computer software]. Dassault Systèmes, Waltham, MA.
Adams, P. F., Lay, M. G., and Galambos, T. V. (1964). “Experiments on high strength steel members.”, Lehigh Univ., Bethlehem, PA.
AISC. (2010). “Code of standard practice for steel buildings and bridges.” AISC 303-10, Chicago.
AISC. (2016). “Specifications for structural steel buildings.” ANSI/AISC 360-16, Chicago.
ASCE. (1968). “Design of hybrid steel beams.”, Reston, VA.
AWS (American Welding Society). (2010). “Structural welding code—Steel.” 22nd Ed., AWS D1.1: D1.1M, AWS Committee on Structural Welding, Miami.
CEN (European Committee for Standardization). (2005). “Design of steel structures. Part 1-1: General rules and rules for buildings.” EN 1993-1-1:2005:E, Brussels, Belgium.
Galambos, T. V., and Ketter, R. L. (1959). “Columns under combined bending and thrust.” J. Eng. Mech. Div., 85(EM2), 135–152.
Greiner, R., and Kaim, P. (2001). “Comparison of LT-buckling design curves with test results.”, European Convention for Constructional Steelwork, Brussels, Belgium.
Greiner, R., Salzgeber, G., and Ofner, R. (2001). “New lateral torsional buckling curves —Numerical simulations and design formulae.”, European Convention for Constructional Steelwork, Brussels, Belgium.
Kim, Y. D. (2010). “Behavior and design of metal building frames using general prismatic and web-tapered steel I-section members.” Ph.D. thesis, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta.
Nethercot, D. A. (1976). “Buckling of welded hybrid steel I-beams.” J. Struct. Div., 102(3), 461–474.
Prawel, S. P., Morrell, M. L., and Lee, G. C. (1974). “Bending and buckling strength of tapered structural members.” Weld. J., 53(2), 75–84.
Rebelo, C., Lopes, N., Simões da Silva, L., Nethercot, D., and Vila Real, P. M. M. (2009). “Statistical evaluation of the lateral-torsional buckling resistance of steel I-beams. Part 1: Variability of the Eurocode 3 resistance model.” J. Constr. Steel Res., 65(4), 818–831.
Subramanian, L. P. (2015). “Flexural resistance of longitudinally stiffened plate girders.” Ph.D. thesis, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta.
Subramanian, L. P., Jeong, W. Y., Yellepeddi, R., and White, D. W. (2016a). “Assessment of I-section member LTB resistances considering experimental tests and practical inelastic buckling solutions.”, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta.
Subramanian, L. P., and White, D. W. (2016b). “Evaluation of lateral torsional buckling resistance equations in AISC and AASHTO.” Proc., Annual Stability Conf., Structural Stability Research Council, Nashville, TN.
Subramanian, L. P., and White, D. W. (2016c). “Flexural resistance of longitudinally stiffened I-girders. II: LTB and FLB limit states.” J. Bridge Eng., .
Subramanian, L. P., and White, D. W. (2016d). “Improved noncompact web slenderness limit for I-girders.” J. Struct. Eng., in press.
Subramanian, L. P., and White, D. W. (2016e). “Reassessment of the LTB resistance of rolled I-section members: Moment gradient tests.” J. Struct. Eng., in press.
Subramanian, L. P., and White, D. W. (2017). “Resolving the disconnect between lateral torsional buckling experimental tests and test simulations, and design strength equations.” J. Constr. Steel Res., 128, 321–334.
Toğay, O., Jeong, W. Y., Subramanian, L. P., and White, D. W. (2016). “Load height effects on lateral torsional buckling of I-section members—Design estimates, inelastic buckling calculations and experimental results.”, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta.
Trahair, N., and Hancock, G. (2004). “Steel member strength by inelastic lateral buckling.” J. Struct. Eng., 64–69.
White, D. W. (2008). “Unified flexural resistance equations for stability design of steel I-section members: Overview.” J. Struct. Eng., 1405–1424.
White, D. W., Jeong, W. Y., and Toğay, O. (2016a). “Comprehensive stability design of steel members and systems via inelastic buckling analysis.” Int. J. Steel Struct., in press.
White, D. W., Jeong, W. Y., and Toğay, O. (2016b). “SABRE2.” ⟨white.ce.gatech.edu/sabre⟩ (Sep. 17, 2016).
White, D. W., and Jung, S.-K. (2004). “Unified flexural resistance equations for stability design of steel I-section members—Uniform bending tests.”, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta.
White, D. W., and Jung, S.-K. (2008). “Unified flexural resistance equations for stability design of steel I-section members: Uniform bending tests.” J. Struct. Eng., 1450–1470.
White, D. W., and Kim, Y. D. (2004). “Unified flexural resistance equations for stability design of steel I-section members—Moment gradient tests.”, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta.
White, D. W., and Kim, Y. D. (2008). “Unified flexural resistance equations for stability design of steel I-section members: Moment gradient tests.” J. Struct. Eng., 1471–1486.
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©2016 American Society of Civil Engineers.
History
Received: Apr 21, 2016
Accepted: Sep 1, 2016
Published online: Oct 17, 2016
Published in print: Mar 1, 2017
Discussion open until: Mar 17, 2017
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