Hybrid steel tubular T-joints featuring 3D printed components: optimisation and experimental verification
File(s)
Published version
Author(s)
Hu, Tong
Meng, Xin
Kyvelou, Pinelopi
Macorini, Lorenzo
Gardner, Leroy
Type
Journal Article
Abstract
Wire-arc directed energy deposition (DED-Arc) is well suited to the fabrication of optimised structural connections that often feature intricate geometries with more efficient material distribution for load transfer. In this study, hybrid tubular T-joints featuring DED-Arc components are, for the first time, optimised, manufactured and tested. Topology optimisation was applied to the brace-to-chord junction, with continuous conventional chords retained and DED-Arc-specific fabrication constraints addressed. The optimised designs were initially assessed through nonlinear finite element (FE) analysis, after which seven hybrid and four conventionally welded square hollow section (SHS) T-joints were fabricated and tested under brace compression. The hybrid joints achieved significantly improved structural performance and material efficiency over their benchmark counterparts, driven by two key mechanisms: (1) redistribution of load toward the SHS chord sidewalls, and (2) extension of the effective loading length along the chord, enabled by the optimised DED-Arc components. The greatest gains occurred in joints whose benchmarks exhibited chord face failure and high chord cross-sectional slenderness, with stiffness increases of up to around 2000% and capacity increases of up to almost 500%. These results demonstrate the feasibility and advantages of the hybrid DED-Arc concept integrated with the proposed optimisation workflow and its potential for scalable deployment in efficient and sustainable steel structures.
Date Issued
2026-08-01
Date Acceptance
2026-05-07
Citation
Structures, 2026, 90
ISSN
2352-0124
Publisher
Elsevier BV
Journal / Book Title
Structures
Volume
90
Copyright Statement
© 2026 The Author(s). Published by Elsevier Ltd on behalf of Institution of Structural Engineers. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Publication Status
Published
Article Number
112048
Date Publish Online
2026-06-08