Speaker
Description
The Wire Arc Additive Manufacturing (WAAM) process with Cold Metal Transfer(CMT) has been developed in the past decade to propose an affordable additive manufacturing method offering large efficiency, important added metal rate as well as simple conventional welding technologies. Nevertheless, the control of WAAM CMT processing has to be improved for dissemination in industries as an alternative to other AM processes. Consequently, modelling is of interest to understand the physical phenomena occurring during melting and solidification stages and to estimate final properties of parts. To this end, two approaches are proposed both relying on a framework of level-set formulation and continuum assumptions. The mesoscale formulation provides a thermo-hydraulic transient model of the WAAM CMT process. Surface tension, Marangoni effect and feeding made by droplets when the wire interacts with the melt pool are responsible for the fluid flow and the heat transfer. As electro-magnetic is not resolved, the cyclic wire dynamic is explicitly described with a contact detection model, which represents the process driven by short-circuit. These phenomena are consequently considered in the present approach to provide relevant simulation of bead development and its final morphology. Regarding the part scale, a macroscale formulation is proposed on a segment based scalable heat and mass transfer and a thermo-mechanical resolution. This approach aims at describing a several-hours deposition of matter. Metal is described as a single solid phase, as fluid flow is not considered. Accordingly, this simplified macroscale model aims at predicting distortions and residuals stresses within a part during cooling at an industrial scale. Both models rely on adaptive remeshing, providing accurate results within sustainable computation time. The present research activity gathers multiple experimental data in order to calibrate the meso- and macroscale models.
| Speaker Country | FRANCE |
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