Development of numerical models for wire arc additive manufacturing

Abstract

Computational modelling of Additive Manufacturing offers insight into the complex nature of heat transfer that continuously changes during processing yet is challenging to monitor in-situ. The use of finite element models offers predictions into how geometries, materials and parameters will affect an end part. A process simulation model for directed energy deposition using COMSOL Multiphysics, specifically through the heat transfer module is presented herein. Models examining 1D, 2D and 3D problems whereby heat sources are stationary, moving and moving with layer addition respectively have been built. This enhancement of complexity per model offers users an insight into a sequence which can be utilised to understand what fundamentally needs to be included in models to allow for development. The approach of starting off with something simplistic and then building on complexity allows for easier comparisons to be made when interoperating the extracted data. This methodology allows for strategic planning to determine what elements of the software should be utilised to achieve a novel approach to simulate a multi-layer problem using heat transfer only. The moving point heat source model highlights the importance of considering what traverse length and power to select when used in an additive manufacturing or welding context and how these specific inputs can affect the thermal response. The final model presents a novel approach to simulating a multi-layer problem using heat transfer only in a 3D time dependent thermal model. The model incorporates sophisticated and logical modelling techniques which requires only one physics module in comparison to using predefined nodes that necessitate multiple modules. The unique approach uses a third material to act as an activator. The working model can generate results offering insight into temperature and melt pool distributions. Overall, the information presented should be reusable for different additive manufacturing processes with the same core concept being adapted.

Date of Award	May 2023
Original language	English
Sponsors	North West Centre for Advanced Manufacturing
Supervisor	Shaun McFadden (Supervisor) & Justin Quinn (Supervisor)