Abstract

The impacts of single angular particles on ductile materials can result in large deformations and material chip separation, which cannot be effectively simulated using conventional mesh-based numerical methods. In this study, a novel particle-based mesh-free method called the Lagrangian gradient smoothing method (L-GSM) is first applied to simulate the dynamic process of single diamond-shaped particles impact on metallic surfaces. Based on the theory of L-GSM, a numerical model is established by incorporating the Johnson–Cook plasticity and failure models. Oxygen-free high-conductivity (OFHC) copper which is represented by a series of discrete particles, is selected as the material of the target block. Simulation results show that the L-GSM model can reproduce the typical erosion mechanisms such as cutting, micro-machining and ploughing. The large deformation of plastic craters and material removal are successfully simulated without using any additional techniques to handle the distorted domain. In addition, the computational accuracy and efficiency of the L-GSM are discussed by comparison with different mesh-free models. This study provides an effective numerical model with better accuracy and efficiency, helping to reveal the fundamental erosion mechanisms resulting from the impacts of angular particles.

摘要

单角颗粒对延展性材料的影响会导致大变形和材料切屑分离，使用传统的基于网格的数值方法无法有效模拟。在这项研究中，首先应用一种称为拉格朗日梯度平滑法（L-GSM）的新型基于粒子的无网格方法来模拟单个菱形粒子撞击金属表面的动态过程。基于L-GSM理论，结合Johnson-Cook塑性和失效模型建立了数值模型。选用以一系列离散粒子为代表的无氧高导（OFHC）铜作为靶块的材料。仿真结果表明，L-GSM模型可以再现典型的切削、微加工和耕作等侵蚀机制。无需使用任何其他技术来处理扭曲域，即可成功模拟塑料坑的大变形和材料去除。此外，通过与不同无网格模型的比较，讨论了 L-GSM 的计算精度和效率。这项研究提供了一个具有更高准确性和效率的有效数值模型，有助于揭示角粒子影响导致的基本侵蚀机制。