A novel high-efficient finite element analysis method of powder bed fusion additive manufacturing

This paper aims to develop a high-efficient finite element (FE) model by combining the equivalent boundary condition method (EBCM) and dynamic mesh method (DMM) for accelerating the thermo-mechanical simulation of additive manufacturing by powder bed fusion (PBF). EBCM and DMM take advantage of the strong non-linear phenomenon in the thermo-mechanical affected zone (TMAZ) by simplifying the temperature boundary conditions and optimizing the local mesh density, respectively. In detail, EBCM can reduce the difficulty of convergence in computing, while DMM can reduce the scale of stiffness matrix. The experimentally calibrated lattice Boltzmann method (LBM) firstly is used to produce the equivalent temperature function in TMAZ as the thermal input conditions of the FE model. The thermo-mechanical responses of several PBF deposits under different process parameters are predicted by the developed model, presenting good agreement with experiment data in terms of in-situ temperature and residual stress. Compared with the normal model, the novel high-efficient model notoriously cuts the computation cost without compromising precision. This study provides an important simulation concept for high-efficient FE analyses with high fidelity of the AM technology.