Gaussian process regression with physics-guided features for WLAM bead geometry: Repeated validation, algorithmic baselines, and predictive-interval assessment
Year: 2026
Type: article
Abstract: Wire–laser additive manufacturing (WLAM), also referred to as laser wire-feed directed energy deposition, requires stable bead geometry for dimensional control. This study evaluates Gaussian process regression (GPR) for predicting bead width (WB) and height (HB) from laser power, travel speed, and wire feed speed under a small-data setting. Line energy density and the wire-to-travel ratio are added as physics-guided coordinates; they are deterministic transformations rather than independent observations or governing constraints. One experimental run ( n = 24 ) was used for model development with ten repetitions of five-fold cross-validation, and two later runs ( n = 24 ) were reserved for same-system evaluation. Relative to the three original inputs, feature augmentation reduced repeated-CV GPR RMSE by 5.5% for WB and 24.8% for HB. Augmented GPR achieved repeated-CV R 2 = 0.813 ± 0.026 for WB and 0.957 ± 0.007 for HB; after refitting on all development data, later-run R 2 values were 0.742 and 0.959, respectively. Linear regression and a shallow neural network were competitive for several point metrics, showing that the improvement cannot be attributed to GPR alone. Nominal 95% GPR prediction intervals covered 91.7% of WB and 95.8% of HB later-run observations. The contribution is therefore a controlled assessment combining feature ablation, identical-fold algorithmic baselines, repeated resampling, later-run testing, and predictive-interval coverage assessment. The demonstrated scope is limited to measurable stable tracks in one SS316L machine/process window; broader transfer and experimentally confirmed inverse parameter selection remain future work.
Source: Next Materials
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,280
Funder: Université Grenoble Alpes
OpenAlex ID: W7214542425