New design rules of cold-formed high strength steel CHS-to-RHS X-joints

Pandey, Madhup; Young, Ben

Abstract

Numerical investigation and design of cold-formed high strength steel (CFHSS) X-joints with circular hollow section (CHS) braces and square as well as rectangular hollow section (SHS and RHS) chords are presented in this paper. The steel grades of hollow section members were S900 and S960 with nominal 0.2% proof stresses of 900 and 960 MPa, respectively. The static performances of CHS-to-RHS X-joints were experimentally investigated by the authors. Accurate finite element (FE) models were developed in this study by duly validating the test results, including ultimate capacities, load–deformation histories and failure modes. A comprehensive FE parametric study was then performed using the verified FE models, where the validity ranges of critical geometric parameters were extended beyond the current threshold limits specified in international codes. The nominal strengths predicted from design rules given in European code and Comité International pour le Développement et l'Etude de la Construction Tubulaire (CIDECT) were compared with the ultimate capacities of test and finite element (FE) X-joint specimens. All test and FE X-joint specimens were failed by chord face failure mode and a combination of chord face and chord side wall failure mode, which was termed as a combined failure mode in this investigation. It has been demonstrated that the European code and CIDECT design provisions are unsuitable and uneconomical for the design of cold-formed S900 and S960 steel grades CHS-to-RHS X-joints investigated in this study. As a result, user-friendly, economical and reliable design rules are proposed in this study for the investigated joints.

• Journal Article Type: Article
• Acceptance Date: Feb 14, 2023
• Online Publication Date: May 4, 2023
• Publication Date: 2023-07
• Deposit Date: May 6, 2023
• Publicly Available Date: May 5, 2024
• Journal: Thin-Walled Structures
• Print ISSN: 0263-8231
• Electronic ISSN: 1879-3223
• Publisher: Elsevier BV
• Peer Reviewed: Peer Reviewed
• Volume: 188
• Article Number: 110642
• DOI: https://doi.org/10.1016/j.tws.2023.110642
• Keywords: Design proposals; High performance steel; Hollow section members; Numerical investigation; Tubular joints
• Public URL: https://nottingham-repository.worktribe.com/output/20287686