PSI - Issue 83

C. Mallor et al. / Procedia Structural Integrity 83 (2026) 130–137

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2.3. Surrogate Model Development A surrogate model is useful in AM if it reduces computation substantially while retaining the trends that matter to process engineers. In this work, the surrogate was not trained directly on raw experimental data alone. Instead, experiments were first used to validate the physics-based model, and the validated model then generated the dataset required for reduced-order approximation. This hierarchy preserves physical meaning while avoiding the cost and variability associated with large fully experimental campaigns. The reduced-order method selected for the study was the Twinkle library, which uses tensor rank decomposition (TRD) as a non-intrusive ROM technique [10]. A schematic of the Twinkle architecture is shown in Fig. 6.

Fig. 6. The three main blocks of Twinkle library: ROM definition, ROM calculation, and ROM evaluation, from left to right. Adapted from [10].

For the benchmark, the reduced one-dimensional functions that describe and predict the model behaviour correspond to laser power, scan speed, and preheating. The functions themselves provide interpretability to the model, making it possible to inspect how each input variable contributes to the predicted output deflection. 3. Results and discussion The results are presented in the same sequence as the methodology: analysis of the experimental campaign, validation of the full-order model, and discussion of the ROM-based surrogate model. The reliability of the surrogate depends on the reliability of the physics-based model from which it is derived. The experimental campaign considered different process parameters and levels under a design of experiments (DOE) approach. The dataset was organized through a full-factorial DOE involving three levels for each of the three process parameters. Laser power was explored at 96, 120, and 144 W; scan speed at 800, 1000, and 1200 mm/s; and preheating at 21, 200, and 400 ºC. This generated 27 benchmark conditions. In terms of the parts layout, four twin-cantilevers were arranged on each build plate, as shown in Fig. 7.

Fig. 7. Build job of four twin-cantilevers after partial cutting from the build plate.