Numerical Modelling of Directed Energy Deposition and Experimental Validation Based on Digital Image Correlation

This contribution presents a combined approach for in-situ experimental characterisation and numerical modelling of thermo-mechanical behaviour in directed energy deposition (DED). Full-field temperature and substrate deformation are measured simultaneously using infrared (IR) thermography and stereo digital image correlation (DIC) during laser-beam powder deposition on a thin substrate. The experimental data are used to calibrate thermal boundary conditions and to validate a macroscopic finite-element model. The validated framework is then applied to compare different deposition strategies, demonstrating the capability of the coupled measurements and simulations to capture transient thermal fields, deformation evolution and toolpath-dependent effects relevant for process optimisation.