Numerical simulation of metallic wire arc additive manufacturing (WAAM)

Thermo-Mechanical Modelling of Wire-Arc Additive Manufacturing (WAAM) of Semi-Finished Products

“…In the numerical model, the double-ellipsoidal heat source according to Goldak [22] was considered. This is a typical approach for common arc-welding simulations, and replicates the thermal energy input well [13,14,19,22]. The underlying energy density function subdivides the weld pool along the welding path (z-axis) into the front (cf) and rear areas (cr), and is primarily dominated by the welding power [22].…”

“…For a holistic approach to the material behaviour in the numerical simulation, the elastic-plastic material properties are necessary. Hence, the temperature-dependent Young's modules (see Figure 2) and the flow curves (see Figure 3) for both materials under technologically relevant parameters were also established and implemented in the FE software MSC Marc (MSC Software Corporation now Hexagon AB, Newport Beach, CA, USA), as tables [14].…”

“…All welding layers had gluing contacts between them, for the purposes of observing the heat transfer between them. In order that the temperature distribution could be calculated properly, the base plate was also modelled and, on the lower surface, a heat-transfer coefficient to the welding table was defined by the Thermal Face Flux condition (for steel with α G4Si1 = 2000 W/m 2 /K, and for magnesium with α AZ31 = 100 W/m 2 /K) [14,21]. The heat-transfer coefficient to the environment was α air = 35 W/m 2 /K for all numerical investigations.…”

“…The 'element birth and death' method was applied to the investigated deposition process, for which the melting temperature was employed as the activation criterion. A melting point of ϑ melt,AZ31 = 630 • C [17] was defined for the AZ31 alloy, and JMatPro calculated a melting point of ϑ melt,G4Si1 = 1503 • C for G4Si1 based on chemical composition [14]. This modelling method deactivates all elements of the weld seam until the melting point is reached, at which point all elements are activated and their material properties are considered.…”

“…On the other hand, additive technologies, such as WAAM or wire laser metal deposition (LMD-W), can also be modelled by a Finite Element (FE) method based on the element-birth technique, for the determination of real temperature fields and residual stresses. The focus for this simulation of the WAAM process has been on calculating temperature distribution, displacement of components and residual stresses [11][12][13][14][15][16]. The focus of this paper is not on powder-bed methods.…”