An improved high order smoothed particle hydrodynamics method for numerical simulations of selective laser melting process

Abstract

Metal selective laser melting (SLM) is an important Additive Manufacturing (AM) technology, which directly melts and solidifies metal parts by heating metal or alloy powder with laser. High-fidelity numerical simulations could provide tools for insight investigations of the SLM processes. In this study, an improved high order smoothed particle hydrodynamics (SPH) method was developed to simulate the melting and solidification process of metal selective laser melting. In the improved high order SPH model, the improved kernel gradient correction (KGC) is developed to overcome the non-conservation problem of traditional KGC. And an improved surface tension model is developed to improve the stability and accuracy of modeling the surface tension. In order to establish the numerical model for simulating the SLM forming process, the Gaussian heat source model and melting latent heat model are introduced. Moreover, particle shifting technology integrated with X-SPH technology are applied to improve the uniform of particle distributions stability of calculation. A number of test examples are investigated with the improved high order SPH, and compared with results from other approaches including traditional SPH. From the obtained numerical results, we can conclude the improved high order SPH is effective in modeling the melting and solidification process of SLM.