Full-field validation of a thermo-mechanical model for directed energy deposition using IR thermography and stereo DIC

Kovšca, Dejan (avtor), Starman, Bojan (avtor), Govekar, Edvard (avtor), Mole, Nikolaj (avtor), Halilovič, Miroslav (avtor)

This paper presents a thermo-mechanical finite element (FE) modelling framework for laser-based directed energy deposition (DED-LB) that is validated and calibrated using a novel full-field, in-situ experimental approach. The measuring setup combines infrared (IR) thermography and stereo digital image correlation (DIC) to enable continuous, non-intrusive, full-field measurement of transient temperature and displacement fields on the substrate without interfering with the DED process. These measurements provide direct input for reliable model calibration and a consistent basis for full-field validation of both thermal and mechanical response of the numerical model. The calibrated FE model accurately reproduces the measured thermal histories and the evolution of substrate deformation throughout the process. Based on the validated model, the dominant deformation mechanisms are identified, highlighting the combined effects of thermal gradients, contraction of the solidifying deposited material, and mechanical boundary conditions. The study further introduces a new analytical bead-geometry modelling method that estimates the geometry of initial and overlapping beads without additional experiments and establishes a consistent link between realistic and simplified bead representations while preserving deposited mass and heat input. Comparative simulations demonstrate that simplified rectangular bead profiles can reduce computational cost by up to 70% with only minor loss of accuracy, making them suitable for parametric studies. Finally, different DED strategies are evaluated, showing that an inward-spiral strategy leads to the lowest substrate deformation and the most uniform residual-stress distribution, whereas unidirectional and bidirectional strategies produce larger deflections and stronger springback.

• Jezik: Angleški jezik
• Ključne besede: directed energy deposition, thermo-mechanical modelling, residual stress and deformation, digital image correlation
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: 26 str.
• Številčenje: Vol. 258, art. 104554
• PID: 20.500.12556/RUL-181709
• UDK: 004.9
• ISSN pri članku: 1872-6925
• DOI: 10.1016/j.finel.2026.104554
• COBISS.SI-ID: 275099395
• Datum objave v RUL: 14.04.2026

Gradivo je del revije

• Naslov: Finite elements in analysis and design
• Založnik: Elsevier
• ISSN: 1872-6925
• COBISS.SI-ID: 23024645

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: usmerjeno nanašanje materiala, termo-mehansko modeliranje, zaostale napetosti in deformacije, korelacija digitalnih slik