Resonant ultrasound spectroscopy for predicting residual stresses in additively manufactured components with multiple hybrid layers

Current techniques for measuring residual stresses in additively manufactured components face certain limitations, often related to their sensitivity or the fact that they are destructive. Resonant ultrasound spectroscopy (RUS) has shown promise for evaluating residual stresses in additively manufactured components with single hybrid layers. Hybrid additive manufacturing (AM) incorporates additional energy sources or processes to create functionally graded components at specific locations. Each hybrid step or layer contributes to grain refinement and increased dislocation density which thereby alter residual stresses. In this presentation, the use of RUS to evaluate samples with multiple hybrid layers is described for samples created using three hybrid processes: milling, laser peening, and ultrasound peening. Prospects for determining residual stresses and layer locations are evaluated and issues related to non-uniqueness are discussed. This research lays the groundwork for measuring residual stress in hybrid components through experimental RUS measurements, finite element modeling, and machine learning algorithms.