eprintid: 10195527 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/19/55/27 datestamp: 2024-08-07 14:31:34 lastmod: 2024-08-07 14:31:34 status_changed: 2024-08-07 14:31:34 type: article metadata_visibility: show sword_depositor: 699 creators_name: Possidente, Luca creators_name: Couto, Carlos creators_name: Tondini, Nicola creators_name: Real, Paulo Vila title: Review of design approaches for steel columns subjected to localised fires: Insights from the 2nd generation Eurocode model ispublished: pub divisions: UCL divisions: B04 divisions: F44 keywords: Fire design, Thermal gradients, Localised fires, Advanced analysis, Analytical methods, Steel columns, Resilient infrastructures note: Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). abstract: Complex temperature fields may develop inside structural steel elements in fire, severely affecting the local and global response of the structure. However, simplified yet well-accepted design procedures allow for uniform temperature distributions in the steel elements. The second generation of Eurocodes provides advanced models for localised fires where non-negligible thermal gradients both inside the sections and along the elements are expected to influence the resistance of steel elements, especially those critical to the stability of the entire structure, such as vertical members. This paper sheds some light on the consequences of employing procedures with increasing complexity in the design of unprotected axially compressed steel columns subjected to localised fires for which the effect of the smoke layer is not significant. Five procedures were compared, considering a refinement in both the thermal and the mechanical models, culminating in the application of a procedure enabling complex temperature fields both in the section and along the column, namely the LOCAFI model, and exploiting numerical simulation in SAFIR. A parametric study was conducted, encompassing different fire scenarios and structural characteristics, resulting in 27468 analyses. It was shown that in the case of localised fire scenarios that induce significant thermal gradients in the structure advanced modelling is recommended because it better captures the thermomechanical response. Detailed considerations on relevant outcomes, such as the temperature at failure, were provided. Finally, the influence of the surrounding structure on the effectiveness of the procedures was investigated extending the parametric analysis to columns with various degrees of axial restraints. date: 2024-09-15 date_type: published publisher: ELSEVIER SCI LTD official_url: https://doi.org/10.1016/j.engstruct.2024.118424 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2290605 doi: 10.1016/j.engstruct.2024.118424 lyricists_name: Possidente, Luca lyricists_id: LPOSS45 actors_name: Possidente, Luca actors_id: LPOSS45 actors_role: owner funding_acknowledgements: EP/X032469/1 [UK Research and Innovation (UKRI) Institution]; CEECINST/00026/2018 [FCT - Fundacao para a Ciencia e a Tecnologia, I.P.]; L 232/2016 [Italian Ministry of Education, University and Research (MIUR)] full_text_status: public publication: Engineering Structures volume: 315 article_number: 118424 pages: 15 issn: 0141-0296 citation: Possidente, Luca; Couto, Carlos; Tondini, Nicola; Real, Paulo Vila; (2024) Review of design approaches for steel columns subjected to localised fires: Insights from the 2nd generation Eurocode model. Engineering Structures , 315 , Article 118424. 10.1016/j.engstruct.2024.118424 <https://doi.org/10.1016/j.engstruct.2024.118424>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10195527/1/Possidente%20et%20al%20%282024%29%20Review%20of%20design%20approaches%20for.pdf