I am a Ph.D. student at the Solid Mechanics Laboratory (LMS) of École Polytechnique since October 2025, supervised by Manas V. Upadhyay and Daniel Weisz-Patrault. My thesis, Rapid identification of laser processing–microstructure–properties relationship: an experiment–machine learning synergistic approach, uses machine learning to predict the microstructure and mechanical properties of metal parts made by additive manufacturing, starting from the laser process parameters. I work in the Thermomechanics and Materials Engineering (TME) group, and the experiments are done in situ, with a continuous-wave laser inside a scanning electron microscope (Laser-SEM).
To model the thermal history of the process, I developed a spectral Galerkin solver for nonlinear transient heat transfer. It reproduces high-fidelity finite-element temperature fields within 1% while running up to 227 times faster on GPU, which makes large simulation campaigns for machine learning affordable.
During my engineering studies I did internships at ArianeGroup, Withings and Aerophile. I care about research that transfers to industry: methods that are validated against reference solutions, fast enough to use in practice, and released as open-source tools.
This work is partly supported by the French Defence Innovation Agency (AID) via CIEDS (project LaserSurf) and by the French National Research Agency (ANR-24-CE08-3737).
Full list: Google Scholar · ORCID
Efficient spectral Galerkin framework for nonlinear transient heat transfer in finite domains
A spectral Galerkin method for the fully nonlinear transient heat equation. On rapid laser–metal interactions it reproduces high-fidelity finite-element temperature fields with less than 1% relative error at 227-fold faster GPU runtimes. Applied to a part-scale laser scanning study, accounting for evaporation and latent heat more than halves the proposed processing metric.
@misc{andrieux2026spectral,
title = {Efficient spectral Galerkin framework for nonlinear transient heat transfer in finite domains},
author = {Andrieux, Th{\'e}o and Ntinos, Andreas and Upadhyay, Manas V.},
year = {2026},
eprint = {2609.22268},
archivePrefix = {arXiv},
primaryClass = {cond-mat.mtrl-sci},
doi = {10.48550/arXiv.2609.22268},
url = {https://arxiv.org/abs/2609.22268}
}spectral_galerkin_heat
Semi-analytical modal solver for the fully nonlinear heat equation on cuboid domains, for laser surface treatments and additive manufacturing. Companion code of the preprint above, with worked examples.