Selective laser melting (SLM) is an advanced additive manufacturing technology related to the powder bed fusion (PBF) process. Numerical simulation is the key means of realizing the shape and property control of components for additive manufacturing. In this paper, an improved smoothed particle hydrodynamics (SPH) method is proposed for the numerical simulation of the SLM process, focusing on the melt pool flow. The accuracy of calculations at the free surface is significant for modeling the SLM process and there are kernel function truncation errors of the SPH method at the free surface. Therefore, an improved kernel gradient correction (KGC) technique and an improved continuous surface tension model are proposed to improve the accuracy of calculations at the free surface. The KGC technique can improve the accuracy of the kernel gradient in SPH approximation, however, the accuracy of KGC will decrease on the free surface. To improve the computational accuracy on the free surface, an improved KGC is developed. The surface tension model is significant for the numerical simulation of the SLM process, and an improved continuous surface tension (CSF) model is developed to enhance the stability and accuracy of surface tension modeling. In addition, a Gaussian heat source model and a latent heat model are introduced in the improved SPH model. The accuracy and effectiveness of the present SPH method for simulating the melting and melt pool flow of the SLM process are also verified by four numerical examples.

中文翻译：

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SPH 中纳入改进的 CSF 模型和改进的 KGC 技术，用于模拟选择性激光熔化过程


选择性激光熔化（SLM）是一种与粉末床熔融（PBF）工艺相关的先进增材制造技术。数值模拟是实现增材制造零部件形状和性能控制的关键手段。本文提出了一种改进的平滑粒子流体动力学（SPH）方法，用于 SLM 过程的数值模拟，重点关注熔池流动。自由表面计算的精度对于SLM过程建模具有重要意义，而SPH方法在自由表面存在核函数截断误差。因此，提出了改进的核梯度校正（KGC）技术和改进的连续表面张力模型来提高自由表面的计算精度。 KGC技术可以提高SPH近似中核梯度的精度，但在自由表面上KGC的精度会下降。为了提高自由表面上的计算精度，开发了改进的KGC。表面张力模型对于SLM过程的数值模拟具有重要意义，并且开发了改进的连续表面张力（CSF）模型以提高表面张力建模的稳定性和准确性。此外，改进的SPH模型还引入了高斯热源模型和潜热模型。通过四个数值算例也验证了本文SPH方法模拟SLM工艺熔化和熔池流动的准确性和有效性。