Computational process modelling of metal additive manufacturing has gained significant research attention in recent past. The cornerstone of many process models is the transient thermal response during the AM process. Since deposition-scale modelling of the thermal conditions in AM is computationally expensive, spatial and temporal simplifications, such as simulating deposition of an entire layer or multiple layers, and extending the laser exposure times, are commonly employed in the literature. Although beneficial in reducing computational costs, the influence of these simplifications on the accuracy of temperature history is reported on a case-by-case basis. In this paper, the simplifications from the existing literature are first classified in a normalised simplification space based on assumptions made in spatial and temporal domains. Subsequently, all types of simplifications are investigated with numerical examples and compared with a high-fidelity reference model. The required numerical discretisation for each simplification is established, leading to a fair comparison of computational times. The holistic approach to the suitability of different modelling simplifications for capturing thermal history provides guidelines for the suitability of simplifications while setting up a thermal AM model.

中文翻译：

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金属增材制造工艺部分规模热建模中常见简化的分类和分析

金属增材制造的计算过程建模近年来引起了广泛的研究关注。许多工艺模型的基石是增材制造工艺期间的瞬态热响应。由于增材制造中热条件的沉积规模建模计算成本高昂，因此文献中通常采用空间和时间简化，例如模拟整个层或多层的沉积以及延长激光曝光时间。尽管有利于降低计算成本，但这些简化对温度历史准确性的影响是根据具体情况报告的。在本文中，首先根据时空域的假设将现有文献中的简化分类到归一化简化空间中。随后，通过数值示例研究所有类型的简化，并与高保真参考模型进行比较。建立每个简化所需的数值离散化，从而实现计算时间的公平比较。针对捕获热历史的不同建模简化适用性的整体方法为建立热增材制造模型时简化的适用性提供了指导。