Multi-Physics Simulation of Material Extrusion-Based Additive Manufacturing Process: Towards Understanding Residual Stress Formation

Understanding the material extrusion-based process is critical for better mechanical properties and print quality. This work focuses on numerical simulation of the material extrusion-based process, particularly examining residual stresses in the strand. The simulations are performed using the finite element method, with the arbitrary Lagrangian-Eulerian (ALE) method being used to solve the free surface. Residual stresses are examined by solving the non-isothermal thermo-mechanical flow problem. A generalized Newtonian and viscoelastic models are used to simulate the material extrusion-based process and evaluate their ability to explain residual stresses. This study investigates the distribution of residual stresses along the printed strand and the printed strand’s cross-section. The effect of different printing process parameters, such as bed temperature, nozzle temperature, and printing speed, on residual stresses is studied. An experimental study is conducted to investigate the impact of printing speed on the bending of the printed strand to validate simulation findings. These results provide insight into the residual stresses in printed parts. They can aid in optimizing the material extrusion-based process parameters needed for achieving desired mechanical properties in printed parts.