Flexural-torsional buckling strength of I-girders with discrete torsional braces under various loading conditions

Canh Tuan Nguyen, Hyun Sung Joo, Jiho Moon, Hak Eun Lee

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Torsional bracing systems have been used widely in I-girder bridges to increase the flexural-torsional buckling strength and distribute the load to the adjacent girders. To evaluate the required stiffness of the bracing and the flexural-torsional buckling strength of the I-girder with a multiple torsional bracing system, the equivalent continuous torsional bracing concept is often adopted regardless of the type of torsional bracing system. However, a previous study on the I-girder with discrete torsional bracings under uniform bending reported that the equivalent continuous torsional bracing concept has certain limitations on discrete torsional bracing problems and it needs to be investigated for general loading cases. This article presents an analytical solution for the elastic flexural-torsional buckling strength and stiffness requirements of I-girders with discrete torsional bracings under various loading conditions. First, a review was performed of the previous study on the elastic critical buckling moment and torsional stiffness requirement of the I-girder with discrete torsional bracings under uniform bending. This solution was then extended for various loading conditions. From the derived analytical solutions, the equivalent moment factor was proposed for practical engineering purposes and the proposed solutions were verified by comparing them with the results of finite element analysis and those of other previous studies. Finally, non-linear finite element analyses including the effects of the initial imperfection and residual stresses were conducted to examine the inelastic buckling strengths of I-girders with discrete torsional bracings under various loading conditions. The results showed that the buckling curves from the current design specification provide reasonably conservative flexural-torsional buckling strengths of the I-girder with discrete torsional bracings when the proposed elastic solutions are applied to obtain the buckling parameters.

Original languageEnglish
Pages (from-to)337-350
Number of pages14
JournalEngineering Structures
Volume36
DOIs
Publication statusPublished - 2012 Mar 1

Fingerprint

Beams and girders
Buckling
Stiffness
Residual stresses
Specifications
Finite element method
Defects

Keywords

  • Bifurcation analysis
  • Equivalent moment factor
  • Flexural-torsional buckling
  • Inelastic buckling
  • Stiffness requirement
  • Torsional bracing
  • Torsional restraint

ASJC Scopus subject areas

  • Civil and Structural Engineering

Cite this

Flexural-torsional buckling strength of I-girders with discrete torsional braces under various loading conditions. / Nguyen, Canh Tuan; Joo, Hyun Sung; Moon, Jiho; Lee, Hak Eun.

In: Engineering Structures, Vol. 36, 01.03.2012, p. 337-350.

Research output: Contribution to journalArticle

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