dc.contributor.advisor |
Clifton, Charles |
|
dc.contributor.author |
Hasanali, Maryam |
|
dc.date.accessioned |
2024-06-30T23:34:08Z |
|
dc.date.available |
2024-06-30T23:34:08Z |
|
dc.date.issued |
2024 |
en |
dc.identifier.uri |
https://hdl.handle.net/2292/68925 |
|
dc.description.abstract |
This study aims to provide an in-depth insight into the structural behaviour and design of the cold-formed steel (CFS) warping-restrained structural components subjected to combined actions sourced from gravity and lateral loads (i.e., beam-columns). A literature study exposes
a lack of understanding of this subject and a need for the development of more precise design
formulas for the design of CFS warping-restrained beam-columns.
This study first evaluated the reliability of the Direct Strength Method (DSM) as specified in
the American Iron and Steel Institute (AISI-S100) and Australian/New Zealand Standard
(AS/NZS-4600), as well as the design methods proposed in the literature for estimating the
load-carrying capacity of the CFS warping-restrained beam-columns. This investigation was
conducted using a comprehensive dataset of beam-column capacities, generated based on
detailed experimentally validated Finite Element (FE) models of CFS elements, considering
material nonlinearity and initial geometric imperfections. The results indicated that the
estimated capacity of beam-columns is significantly affected by the errors associated with (i)
warping-restrained boundary condition effects, (ii) using equations for the calculations of
buckling loads, and (iii) using the code-prescribed linear interaction equation.
Subsequently, the structural performance and potential failure mechanisms of the CFS members
subjected to various load combinations of compression and bending were assessed. The results
were then used to improve the strength predictions of the beam-columns by proposing a general
trinomial expansion representing curved surfaces for the interaction of axial compression and
bending as a function of slenderness ratios. Next, to maximise the efficiency of the codeprescribed
linear interaction equation, other new interaction expressions were developed using
an Artificial Bee Colony (ABC) optimisation algorithm. Different exponent parameters have
been proposed for minor- and major-axes bending, which result in a considerable improvement
in the accuracy of the beam-column strength predictions compared to the existing methods.
Lastly, the beneficial effects of additional restrained warping at the supports of CFS pinended
columns with different lengths, cross-sectional dimensions, and shapes were evaluated using a comprehensive parametric study. Then, more precise and practical design
equations aligned with the DSM have been developed for predicting the strength of these
elements, considering various cross-sectional shapes. |
|
dc.publisher |
ResearchSpace@Auckland |
en |
dc.relation.ispartof |
PhD Thesis - University of Auckland |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. |
|
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.rights.uri |
http://creativecommons.org/licenses/by-nc-nd/3.0/nz/ |
|
dc.title |
Behaviour and Design of Cold-Formed Steel Members Subjected to Combined Axial Compressive Load and Bending Moment |
|
dc.type |
Thesis |
en |
thesis.degree.discipline |
Philosophy |
|
thesis.degree.grantor |
The University of Auckland |
en |
thesis.degree.level |
Doctoral |
en |
thesis.degree.name |
PhD |
en |
dc.date.updated |
2024-06-30T23:15:56Z |
|
dc.rights.holder |
Copyright: The author |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |