Distortional Buckling of Steel I-Section Beams


Distortional buckling of I-beams can occur in two lateral and restrained modes. Lateral-distortional mode of buckling is classified as local-global coupling which involves local changes in the cross-section geometry in addition to lateral displacement and twist. Restrained distortional mode of buckling, also, can occur due to applied restraints against rigid cross-sectional movements of one of the flanges. Compared to the two well-known local and lateral torsional buckles, distortional buckling is relatively more complicated and less documented.

Hence, further research work is still required to better understand and properly address this mode of buckling. This paper presents a review of some recently-published studies by the first author on the subject of distortional buckling of I-beams with the aim of providing some potential research avenues for fruitful future investigations.

Lateral-distortional buckling takes place in intermediate-length members with slender webs as a result of interaction between local and lateral-torsional modes of buckling. It is characterized by simultaneous distortion and lateral deflection of the cross-section. Restrained distortional buckling, on the other hand, can occur due to applied restraints against rigid cross-sectional movements of one of the flanges.

Considering the complexity of the distortional buckling mode, good comprehension and accurate evaluation of this phenomenon can result in the development of effective design guidelines and better performance of structures. Нis paper provides a review of the research work carried out by the first author over the past 15 years or so on the experimental verification of distortion in I-beams, numerical simulation using finite strip method, application of extrapolation techniques for accurate test-data analysis, and assessment of the AISC 360 6pecification considerations. The objective is to demonstrate the different research avenues and provide useful indications for future experimental, numerical, and analytical investigations.

Finite Strip Analysis using CUFSM

The analysis of elastic distortional buckling of simply supported I-beams in uniform bending, using a finite strip analysis program, CUFSM, was performed by Zirakian. CUFSM was originally developed to support research on the behaviour and design of cold formed steel members. Нe accuracy of this program was shown to be good through comparison with established distortional buckling solutions. Нe buckling-response analysis of a typical I-beam in bending showed that the FSM solution does not provide distinct distortional minimum for I-sections. However, distortional buckling mode was identified through visual analysis of the deformed buckling mode shapes at intermediate half-wavelengths between local and lateral buckles.

Impact Factor: 0.64*

ISSN: 2472-0437

Current Issue: Volume 5: Issue 1

Journal of steel structures and construction welcomes submissions with cutting-edge research in the field of Steel. Unsolicited manuscripts including research articles, commentaries, and other reports will also be considered for publication and should be submitted either online or through mail.

You may submit your paper as an attachment at steelstructures@oajournal.org  or steelstruct@businessjournal.org

Online Submission:

Submit your Manuscript online https://www.scholarscentral.org/submissions/steel-structures-construction.html or by mailing to us at steelstructures@oajournal.org

Author Information: Complete names and affiliation of all authors, including contact details of corresponding author (Telephone, Fax and E-mail address).

Best Regards,
Editorial Manager,
Journal of Steel Structures and Construction
Contact: +44-20-3608-4181