A good understanding of the heat transfer in fused filament fabrication is crucial for an accurate stress prediction and subsequently for repetitive, high quality printing. This work focuses on two challenges that have been presented when it comes to the accuracy and efficiency in simulating the heat transfer in the fused filament fabrication process. With the prospect of choosing correct thermal boundary conditions expressing the natural convection between printed material and its environment, values for the convective heat transfer coefficient and ambient temperature were calibrated through numerical data fitting of experimental thermal measurements. Furthermore, modeling simplifications were proposed for an efficient numerical discretization of infill structures. Samples were printed with varying infill characteristics, such as varying air void size, infill densities and infill patterns. Thermal measurements were performed to investigate the role of these parameters on the heat transfer and based on these observations, possible modeling simplifications were studied in the numerical simulations.

翻译：充分理解熔融沉积成型过程中的传热特性对于精确预测热应力及实现可重复的高质量打印至关重要。本研究聚焦于模拟该工艺传热过程时面临的两个关键挑战：精度与效率问题。为合理选取表征打印材料与环境间自然对流的边界条件，通过实验热测量数据的数值拟合对对流换热系数和环境温度进行了校准。此外，针对填充结构的高效数值离散化提出了模型简化方案。实验制备了具有不同填充特性的试样（包括气孔尺寸、填充密度及填充图案的差异），通过热测量实验探究这些参数对传热行为的影响，并基于观测结果在数值模拟中研究了可行的模型简化方案。