Cold-formed high strength steel CHS-to-RHS T- and X-joints: Performance and design after fire exposures

Pandey, Madhup; Young, Ben

Abstract

The post-fire structural performance of cold-formed high strength steel (CFHSS) T- and X-joints with circular hollow section (CHS) braces and square and rectangular hollow section (SHS and RHS) chords is numerically investigated in this study. The tubular members had the nominal 0.2% proof stress of 900 MPa. The CHS-to-RHS T- and X-joints were subjected to compression loads through brace members. The nominal values of peak fire temperatures () were 300°C, 550°C, 750°C and 900°C. Tests carried out by the authors investigating the post-fire static response of cold-formed S900 steel grade CHS-to-RHS T- and X-joints were formed the basis of the numerical investigation carried out in this study. The test results reported by the authors were used to develop accurate finite element (FE) models. The validated FE models were used to perform extensive numerical parametric studies comprising 768 FE specimens. The validity ranges of critical geometric parameters were extended beyond current limits mentioned in international codes and guides. The residual strengths of test and FE specimens were compared with the nominal resistances predicted from design equations given in Eurocode 3 and Comité International pour le Développement et l’ Etude de la Construction Tubulaire (CIDECT) Design Guide 3 using the measured post-fire residual material properties. Generally, design rules given in Eurocode 3 and CIDECT are shown to be quite conservative with very dispersed and unreliable predictions. As a result, accurate and reliable design rules are proposed in this study.

Citation

Pandey, M., & Young, B. (2023). Cold-formed high strength steel CHS-to-RHS T- and X-joints: Performance and design after fire exposures. Thin-Walled Structures, 189, Article 110793. https://doi.org/10.1016/j.tws.2023.110793

• Journal Article Type: Article
• Acceptance Date: Apr 18, 2023
• Online Publication Date: Jun 20, 2023
• Publication Date: Aug 1, 2023
• Deposit Date: Sep 9, 2023
• Publicly Available Date: Jun 21, 2024
• Journal: Thin-Walled Structures
• Print ISSN: 0263-8231
• Electronic ISSN: 1879-3223
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 189
• Article Number: 110793
• DOI: https://doi.org/10.1016/j.tws.2023.110793
• Public URL: https://nottingham-repository.worktribe.com/output/22186765
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0263823123002719?via%3Dihub
• Additional Information: This article is maintained by: Elsevier; Article Title: Cold-formed high strength steel CHS-to-RHS T- and X-joints: Performance and design after fire exposures; Journal Title: Thin-Walled Structures; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.tws.2023.110793; Content Type: article; Copyright: © 2023 Elsevier Ltd. All rights reserved.