A reduced-order model of thermo-viscoelastic filaments in a material extrusion process

High-resolution and high-efficiency simulations are a great challenge in a material extrusion process. This paper developed a reduced-order thermo-viscoelastic model based on discrete differential geometry. This model successfully simulated the dynamic behaviors, heat transfer, and deformations of filaments during the material extrusion with high computational efficiency. The kinematics of filaments was constructed using a centerline and time-parallel frame combined scheme, and the dynamic system was derived based on the elastic and viscous potential energies of stretching, bending, and twisting. A Newmark implicit algorithm was applied to solve the dynamic equations of the model, and a collision detection and response strategy for filaments was proposed. The convergence, accuracy, and efficiency of this model were validated and tested from various aspects. This model was then utilized to examine the impact of printing parameters on the temperature distribution and sagging deformation of an overhanging filament, and its extended applications were further demonstrated.