Phan, D.T., Mojtabaei, S.M., Hajirasouliha, I. orcid.org/0000-0003-2597-8200 et al. (2 more authors) (2020) Design and optimization of cold-formed steel sections in bolted moment connections considering bimoment. Journal of Structural Engineering, 146 (8). 04020153. ISSN 0733-9445
Abstract
The load transfer mechanism in cold-formed steel (CFS) bolted moment connections is mainly through the bolt group in the web of beam elements, which may lead to relatively large bimoment and warping deformations. While the bimoment effects can be considered in the Direct Strength Method (DSM), ignoring the fact that the bolt-group length in the conventional design process can lead to nonconservative solutions. This paper presents an alternative analytical design approach using Eurocode 3 (EC3) effective width method to determine the ultimate flexural strength of CFS bolted moment connections by considering bimoment effects. The results compare very well with previously published experimental test data as well as detailed finite-element models developed in this study. It is shown that a short bolt-group length may lead to up to 25% reduction in the flexural strength of the CFS bolted connections. However, a longer bolt-group length generally results in a moment capacity almost equal to the flexural strength of the CFS channel section. Shape optimization is then conducted using a genetic algorithm (GA) to improve the flexural capacity of the connections by taking into account the bimoment effects. The main design variables are considered to be the relative CFS beam cross-sectional dimensions, while the plate slenderness and dimension limits suggested by EC3 as well as a number of manufacturing and practical end-use constraints are incorporated as design constraints. It is found that, compared with standard cross-sectional dimensions, the optimized sections can improve the flexural strength by as much as 36% for a bolt-group length equal to the depth of beam element.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 American Society of Civil Engineers. This is an author-produced version of a paper subsequently published in Journal of Structural Engineering. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Cold-formed steel (CFS); Bolted moment connection; Bimoment; Bolt-group length; Optimization |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Civil and Structural Engineering (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/L019116/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 29 Mar 2021 09:37 |
Last Modified: | 29 Mar 2021 13:49 |
Status: | Published |
Publisher: | American Society of Civil Engineers (ASCE) |
Refereed: | Yes |
Identification Number: | 10.1061/(asce)st.1943-541x.0002715 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:172624 |