Circular hollow section X-connections near an open chord end: Stress concentration factors

Abstract

This paper presents a numerical finite element (FE) investigation to determine stress concentration factors (SCFs) for circular hollow section (CHS)-to-CHS X-connections near an open chord end. Previous large-scale experiments are used to validate FE models, and a parametric study is performed. The parametric study consists of 240 models with variations in chord slenderness (2γ), branch-to-chord diameter ratio (β), branch-to-chord thickness ratio (τ), and chord end distance (e) on one side of the of the connection. For each of the 240 models, SCFs are determined at the crown and saddle hot-spot stress locations. Extrapolating existing formulae to predict “end-distance effects” on SCFs at these locations in CHS-to-CHS X-connections, from CIDECT Design Guide 8 (DG8), is shown to be inaccurate. Hence, SCF correction coefficients (ψ) and parametric formulae to estimate ψ (based on e/d0, 2γ and β) are derived.