A1 Journal article (refereed), original research

Distortional buckling of X‐joints made of square hollow cross‐section beams: theoretical energy‐based model


Open Access publication

Publication Details
Authors: Björk Timo, Ahola Antti, Tuominen Niko
Publisher: Ernst und Sohn: OnlineOpen
Publication year: 2019
Language: English
Related Journal or Series Information: Steel construction - design and research
Volume number: 12
Issue number: 1
Start page: 55
End page: 63
Number of pages: 9
ISSN: 1867-0520
eISSN: 1867-0539
JUFO-Level of this publication: 1
Open Access: Open Access publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe2019062021484

Abstract

Current design codes do not consider distortional buckling failure
modes, which can occur in the chord member of a tubular X‐joint loaded
axially by brace members. In this study the critical load for
distortional buckling is established based on the energy method and a
beam on elastic foundation (BEF) approach. In the theoretical model the
capacity is created by elastic bending of the chord faces in their own
planes and elastic bending of the cross‐section as a frame structure.
The theoretical capacity of an X‐joint is compared with numerical
results obtained from finite element analyses (FEAs). Some discrepancy
was found between theoretical model and numerical analysis, with the
theoretical model slightly underestimating the load‐carrying capacity.
Experimental tests show that an X‐joint can be prone to distortional
buckling failure mode. However, detailed scrutiny of distortional
buckling failure in X‐joints is only legitimate for joints made of
high‐strength steel (HSS), because other failure mechanisms are more
critical when conventional steels are used. Nevertheless, designers of X‐joints with rectangular hollow section (RHS) members should be aware
of this potential failure mode.


Last updated on 2020-20-03 at 10:03