In the powder bed fusion process, an accurate prediction of the transient temperature field of a part is essential to calculate the subsequent thermal stress evolution and microstructure propagation in that part. The experimental method is time-consuming and expensive since the temperature field is controlled by many process parameters. Numerical heat transfer models can be used to estimate the temperature field at any time point. However, traditional numerical simulation schemes are not suitable for the layer-wised fabrication process due to the extremely high computational cost. The computational cost mainly relies on the element number and time step size. This research provides a new efficient and part-level simulation scheme based on an open-source finite element library, which is able to adaptively refine and coarsen the mesh and solve finite element equations with multiple processors in a parallel way. Here, a new mesh strategy that aims to reduce the element number while keeping the solution accuracy is developed. The simulation speed is 12× to 18× faster compared with the traditional simulation scheme depending on the scale of the simulated domain and number of processors. Simulation results have been compared with the experimental results of an Inconel 718 component. It is shown that the testing point in the simulation experiences the same thermal cycles of the same point in the experiment. This simulation scheme can also be used to optimize the process parameters such as scanning pattern, scan velocity, and layer thickness and can be easily extended to other additive manufacturing processes.

中文翻译：

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Inconel 718 选择性激光熔化的高效热有限元建模

在粉末床熔合过程中，准确预测零件的瞬态温度场对于计算该零件的后续热应力演变和微观结构传播至关重要。由于温度场受许多工艺参数控制，该实验方法耗时且昂贵。数值传热模型可用于估计任何时间点的温度场。然而，由于极高的计算成本，传统的数值模拟方案不适用于分层制造过程。计算成本主要取决于元素数量和时间步长。本研究提供了一种基于开源有限元库的新型高效零件级仿真方案，它能够自适应地细化和粗化网格，并以并行方式使用多个处理器求解有限元方程。在这里，开发了一种新的网格策略，旨在减少单元数量的同时保持解的准确性。仿真速度比传统仿真方案快 12 到 18 倍，具体取决于仿真域的规模和处理器数量。仿真结果已与 Inconel 718 组件的实验结果进行了比较。结果表明，模拟中的测试点经历了与实验中同一点相同的热循环。该模拟方案还可用于优化工艺参数，例如扫描模式、扫描速度和层厚，并可轻松扩展到其他增材制造工艺。