Experimental investigation on stress concentration factors of cold-formed high strength steel tubular X-joints

Pandey, Madhup; Young, Ben

Abstract

This paper describes a test programme to investigate the stress concentration factors (SCF) of cold-formed high strength steel (CFHSS) traditional (without brace and/or chord rotation) and member-rotated tubular X-joints. The braces of traditional tubular X-joints were made of square, rectangular and circular hollow sections (SHS, RHS and CHS), whereas chords were made of SHS and RHS. The braces of member-rotated tubular X-joints were made of SHS and RHS, whereas chords were made of only SHS. The member-rotated tubular joints include brace-rotated (BR), square bird-beak (SBB) and diamond bird-beak (DBB) tubular joints. The tubular members were cold-formed from thermomechanically control processed (TMCP) S900 and S960 steel grades plates. A total of 15 tests was conducted to investigate the SCF of CFHSS traditional and member-rotated tubular X-joints subjected to brace axial compression loads. The brace and chord members were joined together using the automatic gas metal arc welding process. The measured values of brace width-to-chord width ratio (β) ranged from 0.33 to 0.74, effective brace width-to-chord width ratio (β’) ranged from 0.25 to 0.85, chord width-to-chord thickness ratio (2γ) ranged from 20.5 to 38.7 and brace thickness-to-chord thickness ratio (τ) ranged from 0.66 to 1.27. The experimentally obtained SCF values were compared with the SCF values calculated from the CIDECT [1] and literature [2,3]. It has been demonstrated that the existing SCF parametric equations are generally quite conservative and over-predicted the SCF values for cold-formed traditional and member-rotated tubular X-joints of S900 and S960 steel grades. Moreover, in order to observe the effect of member-rotation(s), the maximum SCF values of the brace and chord members of CFHSS member-rotated tubular X-joints were also compared with the maximum SCF values of CFHSS traditional tubular X-joints.

• Journal Article Type: Article
• Acceptance Date: Apr 12, 2021
• Online Publication Date: Jun 23, 2021
• Publication Date: Sep 15, 2021
• Deposit Date: Mar 29, 2023
• Journal: Engineering Structures
• Print ISSN: 0141-0296
• Electronic ISSN: 1873-7323
• Publisher: Elsevier BV
• Peer Reviewed: Peer Reviewed
• Volume: 243
• Article Number: 112408
• DOI: https://doi.org/10.1016/j.engstruct.2021.112408
• Keywords: Civil and Structural Engineering
• Public URL: https://nottingham-repository.worktribe.com/output/15940463
• Additional Information: This article is maintained by: Elsevier; Article Title: Experimental investigation on stress concentration factors of cold-formed high strength steel tubular X-joints; Journal Title: Engineering Structures; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.engstruct.2021.112408; Content Type: article; Copyright: © 2021 Elsevier Ltd. All rights reserved.