Kabir, Md Imran (2016) Lateral Torsional Buckling of Welded Wide Flange Beams. Masters thesis, Concordia University.
Preview |
Text (application/pdf)
3MBKabir_MASC_F2016.pdf - Accepted Version Available under License Spectrum Terms of Access. |
Abstract
Abstract
Lateral Torsional Buckling of Welded Wide Flange Beams
Md. Imran Kabir
Lateral Torsional Buckling (LTB) can be defined as a combination of lateral displacement and twisting due to an application of load on an unsupported beam. Design specifications of Canada CSA S16-14 provides solutions for LTB of welded and rolled beams that were derived for constant moment situation. Same equations have been used over the years for design of rolled and welded shape beams. A recent study has shown that the current code equations might overestimate the capacity of the welded wide shape beams, which make them unsafe to use. Thus a detailed study is required to evaluate the existing LTB equations for welded wide flange (WWF) shapes. This thesis evaluates the performance of current equations in providing LTB capacities of WWF shape beams. A nonlinear finite element (FE) model is developed to investigate the LTB capacity of WWF shape beams. The validated FE model is used to analyze a series of simply supported WWF shape beams with varying unbraced lengths and subjected to equal end moments. Four different patterns of residual stresses and a constant initial imperfection of L/1000 are considered for the analysis. In total, 320 FE models are analyzed, and it is observed that current code overestimates the LTB capacity of WWF shape beams as much as of 37% mainly using the measured residual stress of Lehigh University.
Later, LTB capacity of WWF shape beams subjected to other loading configurations i.e. linear and non-linear moment gradient is investigated. Three types of linear moment gradient are considered i.e. end moment ratio of 0.5, 0.0, -1.0 while for non-linear moment gradient, two types of transverse loading i.e. concentrated load at mid span and uniformly distributed load along the length of the beam are considered in this research. In addition, for transverse loading, the effect of load height is taken into account by changing the position of load at top flange, centroid and bottom flange. Thus, in total 123 and 228 FE models are developed for linear and non-linear moment gradient respectively. From the parametric study conducted for linear moment gradient, it is observed that current CSA S16-14 strength curve overestimates significantly for end moment ratio of 0.5 (40.1%) and 0.0 (34.57%) while it essentially coincides with FE results for end moment ratio of -1.0.
In the case of transverse loading, CSA S16-14 strength curve overestimates by 17% and 33% for concentrated load and distributed load respectively when the load is applied at the top flange of the beam. Unlike the top flange loading, CSA S16-14 strength curve underestimates by 64% and 44% for concentrated and distributed load applied at bottom flange respectively. However, in both cases, CSA S16-14 reasonably matches with the FE results when the load is applied at shear center of the cross-section. In addition, the mean value of equivalent moment factor, ω2 provides good agreement with recommended values by CSA S16-14. In all cases, FE results are compared with other standards i.e. AISC, Eurocode as well as with latest equation proposed by the researchers in University of Alberta. Although, Eurocode is found to be conservative in every cases but proposed equation by the researchers at University of Alberta shows good agreement only in the case of unequal end moment and transverse loading condition. Hence, this equation can be used with a lower resistance factor for LTB strength calculation of WWF beams.
| Divisions: | Concordia University > Gina Cody School of Engineering and Computer Science > Building, Civil and Environmental Engineering |
|---|---|
| Item Type: | Thesis (Masters) |
| Authors: | Kabir, Md Imran |
| Institution: | Concordia University |
| Degree Name: | M.A. Sc. |
| Program: | Civil Engineering |
| Date: | 8 September 2016 |
| Thesis Supervisor(s): | Bhowmick, Anjan |
| Keywords: | Lateral torsional buckling, WWF-beams, finite element, residual stress, simply support, uniform moment, moment gradient factor |
| ID Code: | 981821 |
| Deposited By: | MD IMRAN KABIR |
| Deposited On: | 08 Nov 2016 14:45 |
| Last Modified: | 18 Jan 2018 17:53 |
References:
Abaqus. (2010). "Abaqus standard user’s manual, 6.11." Dassault Systèmes.AISC (2010a). "Specifications for Structural Steel Buildings, ANSI/AISC 360-10", American Institute of Steel Construction, Chicago, IL
Alpsten, G. A. (1972a). "Prediction of thermal residual stresses in hot-rolled plates and shapes of structural steel." 9th IABSE Congress, Final Report, Amsterdam, The Netherlands, pp. 1- 13.
Alpsten, G. A. (1972b)."Residual stresses, yield strength and column strength of hot-rolled and roller-straightened steel shapes." Colloquium on Column Strength, Paris, France, pp. 39-59.
Alpsten, G., and Tall, L. (1970). "Residual stresses in heavy welded shapes." Welding Journal Research Supplement, 49(3), 93s- 105s.
Amin Mohebkhah, and Chegeni, B. (2012). "Local–global interactive buckling of built-up I-beam sections." Thin-Walled Structures, 33-37.
AS 4100. (1998)."Standards Association of Australia", Sydney, Australia.
Baker, K. A. (1984). "Resistance Factors for Laterally Unsupported." Can. J. Civil Eng., 1008 1019.
Beedle, L. S., and Tall, L. (1960). "Basic column strength." ASCE Journal of the Structural Division, 86(ST7): 139- 173.
Bjorhovde, R. (1972). "Deterministic and Probabilistic Approaches to the Strength of Steel Columns." Ph.D. dissertation, Lehigh University, Bethlehem, PA.
Bleich, F. (1952), "Buckling Strength of Metal Structures," McGraw-Hill, New York.
Canadian Standards Association, (CSA). (2014). "Limit States Design of Steel Structures." CAN/CSA-S16-14: Toronto, Ontario, Canada.
Chernenko, D. E., and Kennedy, D. J. (1991). "An Analysis of the Performance of Welded Wide Flange Columns." Can. J. Civil Eng., Vol. 18, pp. 537–555.
Cook, R. D. and D. S. Malkus (2002). "Concepts and applications of finite element analysis." Ed. by W. Anderson. John Wiley & Sons Inc.
Dibley, J. E. (1969). "Lateral Torsional Buckling of I-Sections in Grade 55 Steel." Proc. Inst. Civil Eng., 599–627.
Dux, P.F., and Kitipornchai, S. (1983), "Inelastic Beam Buckling Experiments," Journal of Constructional Steel Research, Vol. 3, No. 1, 3-9
ECCS (1984)."Ultimate limit state calculation of sway frames with rigid joints". Technical Committee 8 33, p. 20
Estuar, F. R., and Tall, L. (1963)."Experimental investigation of welded built-up columns." Welding Journal, Research Supplement, 42(4): 164s- 176s.
Eurocode 3. (2005). EN 1993-1-1 Eurocode 3: "Design of steel structures - Part 1–1: general rules and rules for buildings." European Committee for Standardization (CEN), Brussels, Belgium
Fukumoto Y. (1976)."Lateral buckling of welded beams and girders in HT 80 steel." IABSE congress report, 403-408
Fukumoto, Y., and Itoh, Y. (1981)."Statistical Study of Experiments on Welded Beams." Journal of Structural Division, ASCE, 107 (ST1): 89-103
Fukumoto, Y., and Kubo, M. (1977)."An experimental review of lateral buckling of beams and girders." International Colloquium on Stability of Structures Under static and Dynamic Loads, ASCE, 541-562.
Fukumoto, Y., Itoh, Y., and Kubo, M. (1980)."Strength Variation of Laterally Unsupported Beams." Journal of Structural Division, ASCE, 106 (ST1): 165-181.
Galambos, T. (1968)."Structural Members and Frames." Prentice-Hall, Upper Saddle River, N.J.
Greiner, R. and Kaim, P. (2001)."Comparison of LT-Buckling Design Curves with Test Results."ECCS TC 8 Report 23. European Convention for Constructional Steelwork, Brussels, Belgium
Hassan, R. (2013)."Distortional Lateral Torsional Buckling Analysis for Beams of Wide Flange Cross-Sections." M.A.Sc dissertation, Department of Civil Engineering, Faculty of Engineering, University of Ottawa, Canada.
Helwig, T. A., Frank, K. H., and Yura, J. A. (1997)."Lateral-torsional Buckling of Singly Symmetric I -Beams." Journal of Structural Engineering 123(9), 1172-1179.
Hibbitt Karlsson, Sorensen. (2011)."ABAQUS/Standard User's Manual. Version 6.11." RI: HKS Inc., Pawtucket; 2011.
Kennedy, D.J.L., and Gad Aly, M. (1980). "Limit states design of steel structures-performance factors." Canadian Journal of Civil Engineering, 7(1): 45–77.
Kim, Y.D. (2010). "Behavior and Design of Metal Building Frames Using General Prismatic and Web-Tapered Steel I-Section Members." Doctoral Dissertation, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA.
Kirby, P. A. and D. A. Nethercot (1979)."Design for structural stability." Ed. by M. R. Horne. Granada Publishing Limited
MacPhedran, I., and Grondin, G. (2011)."A Proposed Simplified Canadian Beam Design." Can. J. Civ. Eng. 38: 141-143.
McFalls, R. K., and Tall, L. (1969)."A study of welded columns manufactured from flame-cut plates." Welding Journal Research Supplement, 48(4), 141s- 153s.
Nagaraja Rao, N. R., and Tall, L. (1961)." Residual stresses in welded plates." Welding Journal, Research Supplement, 40(10): 468s -480s.
Nagaraja Rao, N. R., Estuar, F. R., and Tall, L. (1964)." Residual stresses in welded shapes." Welding Journal, Research Supplement, 43(7): 294s -306s.
NCCI (2008)."Elastic critical moment for lateral torsional buckling." SN003a-EN-EU. Steel Construction Institute. Berkshire
Nethercot, D. (1974)."Buckling of welded beams and girders."IABSE publications, 107-121.
Nethercot, D. A. and K. C. Rockey (1971)."A unified approach to the elastic lateral buckling of beams". The structural engineer 49, pp. 321–330
Peraza, D. B. (Feb. 2008). Avoiding Structural failures during construction. url: http://www.structuremag.org/article.aspx?articleID=527
Saatcioglu M, Humar J (2003). "Dynamic analysis of buildings for earthquake resistant design." Can J Civ Eng;30:338–59.
Salvadori, M. G. (1955). "Lateral Buckling of I-beams." American Society of Civil Engineers 120, pp. 1165–1177
Sharifi, S. T. (2015). "Inelastic lateral-torsional buckling capacity of corroded web opening steel beams using artificial neural networks." The IES Journal Part A: Civil & Structural Engineering, 24-40.
Simulia (2013). "ABAQUS/Standard Version 6.12-1", Simulia, Inc. Providence, RI
Subramanian L. and White D.W. (2015), "Evaluation of Lateral Torsional Buckling Resistance Equations in AISC and AASHTO." Proceedings of the Annual Stability Conference, Structural Stability Research Council.
Tall, L. (1964b). "Residual stresses in welded plates."Welding Journal, Research Supplement, 43(1): 10s-23s.
Timoshenko, S. P., and Gere, J. M. (1961). "Theory of Elastic Stability, 2nd ed." McGraw-Hill, New York
Trahair, N. S. (1993). "Flexural-Torsional buckling of structures." CRC Press, Boca Raton, FL.
Vlasov, V. Z. (1961). "Thin- Walled Elastic Beams." Israel Program for Scientific Translations, Jerusalem
Wong, E., and Driver, R.G., (2010). "Critical evaluation of equivalent moment factor procedures for laterally unsupported beams." Engineering Journal, AISC, 2010(Q1). pp. 1–20
Xiao, Q. (2014, April). "Lateral Torsional Buckling of Wood Beams." M.A.Sc dissertation, Departments of Civil Engineering, University of Ottawa, Canada
Ziemian, Ronald D., Editor. (2010). "Guide to Stability Design Criterion for Metal Structures."Hoboken, New Jersy: John Wiley & Sons, Inc.
Repository Staff Only: item control page
Download Statistics
Download Statistics