Construction of Data Sequence for Model Order Reduction in Thermomechanical Modeling of DED Additive Manufacturing

Abstract

Reduced order modeling (ROM) is applied to the finite element thermo-mechanical simulation of metal additive manufacturing at part scale. This is a significant challenge because of the continuously evolving computational domain, on which a local reduced basis is required to apply the projection-based ROM. In this paper, ROM is applied to the mechanical resolution, which is much more time-consuming than the thermal one. Considering the modeling of DED processes (directed energy deposition), it is proposed to organize the training set of simulation snapshots according to an energy deposition length that represents the progress of the process. The full-order model consists of a transient thermomechanical model modified by use of the previously developed Inherent Strain Rate method. When applying the projection-based ROM to this full-order model, the constructed data sequence enables the design a local ROM depending on the energy deposition length and process parameters. The approach, in its present state, is limited to constructions with a constant transverse geometry and a constant set of process parameters. The simulation of the DED construction of a turbine blade mock-up, made of thirty layers with interlayer dwell times, revealed a computational speedup of about 100.