Numerical simulation is an effective approach in studying cutting mechanism. The widely used methods for cutting simulation include finite element analysis and molecular dynamics. However, there exist some intrinsic shortcomings when using a mesh-based formulation, and the capable scale of molecular dynamics is extremely small. In contrast, smoothed particle hydrodynamics (SPH) is a candidate to combine the advantages of them. It is a particle method which is suitable for simulating the large deformation process, and is formulated based on continuum mechanics so that large scale problems can be handled in principle. As a result, SPH has also become a main way for the cutting simulation. Since some issues arise while using conventional SPH to handle solid materials, the total Lagrangian smoothed particle hydrodynamics (TLSPH) is developed. But instabilities would still occur during the cutting, which is a critical issue to resolve. This paper studies the effects of TLSPH settings and cutting model parameters on the numerical instability, as well as the chip formation process. Plastic deformation, stress field and cutting forces are analyzed as well. It shows that the hourglass coefficient, critical pairwise deformation and time step are three important parameters to control the stability of the simulation, and a strategy on how to adjust them is provided.

中文翻译：

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通过拉格朗日光滑粒子总流体动力学对微切削切屑形成的数值研究

数值模拟是研究切削机理的有效方法。切削模拟的广泛使用的方法包括有限元分析和分子动力学。但是，当使用基于网格的配方时，存在一些固有的缺点，并且分子动力学的能力规模非常小。相反，平滑粒子流体动力学（SPH）是将它们的优点结合起来的一种候选方法。这是一种适用于模拟大变形过程的粒子方法，它是基于连续力学制定的，因此原则上可以解决大规模问题。结果，SPH也已成为切削模拟的主要方式。由于使用常规SPH处理固体材料时会出现一些问题，因此开发了总的拉格朗日平滑粒子流体动力学（TLSPH）。但是在切割过程中仍然会出现不稳定性，这是需要解决的关键问题。本文研究了TLSPH设置和切削模型参数对数值不稳定性以及切屑形成过程的影响。还分析了塑性变形，应力场和切削力。结果表明，沙漏系数，成对临界变形和时间步长是控制仿真稳定性的三个重要参数，并提供了一种如何调整它们的策略。