Kiran Abhilash, Li Ying, Hodek Josef, Brázda Michal, Urbánek Miroslav, Džugan Jan
COMTES FHT a.s., Průmyslová 995, 334 41 Dobřany, Czech Republic.
Materials (Basel). 2022 Mar 30;15(7):2545. doi: 10.3390/ma15072545.
The advancement in additive manufacturing encourages the development of simplified tools for deep and swift research of the technology. Several approaches were developed to reduce the complexity of multi-track modeling for additive manufacturing. In the present work, a simple heat source model called concentrated heat source was evaluated for single- and multi-track deposition for directed energy deposition. The concentrated heat source model was compared with the widely accepted Goldak heat source model. The concentrated heat source does not require melt pool dimension measurement for thermal model simulation. Thus, it reduces the considerable time for preprocessing. The shape of the melt pool and temperature contour around the heat source was analyzed for single-track deposition. A good agreement was noticed for the concentrated heat source model melt pool, with an experimentally determined melt pool, using an optical microscope. Two heat source models were applied to multi-track 3D solid structure thermo-mechanical simulation. The results of the two models, for thermal history and residual stress, were compared with experimentally determined data. A good agreement was found for both models. The concentrated heat source model reported less than the half the computational time required for the Goldak model. The validated model, for 3D solid structure thermo-mechanical simulation, was used to analyze thermal stress evolution during the deposition process. The material deposition on the base plate at room temperature results in lower peak temperatures in the layers near the base plate. Consequently, the higher thermal stress in the layers near the base plate was found, compared to the upper layers during the deposition process.
增材制造的进步推动了用于该技术深入快速研究的简化工具的发展。人们开发了多种方法来降低增材制造多道次建模的复杂性。在当前工作中，对一种名为集中热源的简单热源模型进行了评估，用于定向能量沉积的单道次和多道次熔敷。将集中热源模型与广泛认可的Goldak热源模型进行了比较。集中热源模型在热模型模拟中不需要测量熔池尺寸。因此，它减少了大量的预处理时间。分析了单道次熔敷时热源周围的熔池形状和温度等值线。使用光学显微镜观察到，集中热源模型的熔池与实验确定的熔池吻合良好。将两种热源模型应用于多道次三维实体结构热-机械模拟。将两种模型关于热历史和残余应力的结果与实验确定的数据进行了比较。两种模型都吻合良好。集中热源模型所需的计算时间不到Goldak模型的一半。经验证的用于三维实体结构热-机械模拟的模型被用于分析沉积过程中的热应力演变。室温下在基板上进行材料沉积会导致靠近基板的层中峰值温度较低。因此，在沉积过程中，与上层相比，靠近基板的层中发现了更高的热应力。
