A reduced-order modelling procedure for estimating residual stress and distortion in fusion-based metal AM parts

Abstract

There has been a growing interest in understanding and estimating residual stress and distortion in fusion-based metal additive manufacturing (AM) to support process qualification and part certification. This paper presents a reduced-order modeling procedure that provides deeper insights into the residual stress development process and improves computational efficiency by identifying two key parameters that have controlling effects on both the final residual stress state and resulting distortion. One is the plastic zone consisting of both the deposition fusion zone and a region around it and the other is the limit elastic strain state within the plastic zone. A set of closed-form solutions is derived for estimating both the plastic zone boundary and the elastic strain limit. With both parameters being determined, a novel shrinkage strain method is presented for performing simplified finite element simulations of some typical metal AM pass depositions and 3D build scenarios. Validations are then performed by comparing the results obtained from the proposed reduced-order modeling procedure and those from detailed time-history-based thermoplasticity simulations and experimental measurements, demonstrating the effectiveness and computational efficiency of the proposed procedure. This approach provides a practical tool for rapid residual stress estimation and a more comprehensive understanding of residual stress evolution in AM processes.