A study of modeling assumptions and adaptive remeshing for thermomechanical finite element modeling of the LPBF process

Abstract

As-built metallic parts manufactured by the laser powder bed fusion (LPBF) process are usually associated with distortions and high residual stresses due to the high thermal gradients and cycles during the process. Finite element modeling (FEM) could be helpful in simulating the build process and predicting the thermally induced residual stresses and parts’ distortion during or after the process, or after the support structure removal. FEM is, however, computationally expensive without simplifying the boundary conditions and model assumptions. This paper addresses the thermomechanical modeling of the LPBF process in two aspects. Firstly, the effects of model assumptions such as the yield strength, material properties’ temperature dependency, and layer thickness are investigated using 2D models. Secondly, a framework that addressed the computational expense of this modeling problem from the meshing perspective is proposed. The study employed parts from different materials to highlight the importance of model assumptions and demonstrate the effectiveness of the proposed framework.