Development and Analysis of an Optimized Heat Source Model for Wire Arc Additive Manufacturing Using Numerical Simulation

This study aims to develop and analyse Heat Source Models (HSM) used in numerical simulation of Wire Arc Additive Manufacturing (WAAM), which is one of the processes in the Directed Energy Deposition (DED) techniques. The thermal energy distribution of various HSMs is compared to determine their suitability for application in WAAM process simulation. The HSMs are developed in FORTRAN programming language using utility routine and customized subroutine functionality within the Finite Element Modelling (FEM) software MSC Marc/Mentat. The material used for the simulation is 316L austenitic stainless steel and is modelled as a thick wall structure on a plate substrate using 3 strings and 5 layers arrangement. The parameters of the HSM are then optimised and normalised for analysis. The thermal distribution profile of the HSMs is evaluated at various points on the model and compared to the HSMs in current literature. It is hypothesised that a HSM using a modified Gaussian heat distribution would be more suitable for numerical simulation of WAAM process. A flatter peak profile at the center of the modified Gaussian compared to the regular Gaussian distribution would account for the convection effect of the molten pool of the filler metal deposition in a WAAM process.