基于SPH-FEM耦合算法的磨料水射流破岩数值模拟

Numerical simulation of abrasive water jet breaking rock with SPH-FEM coupling algorithm

磨料水射流破岩是一个涉及诸多因素的非线性冲击动力学问题。针对磨料水射流破岩过程的复杂性以及有限元分析法在处理超大变形问题时存在的网格畸变问题,基于光滑粒子(SPH)耦合有限元(FEM)的方法模拟了磨料水射流破岩过程,并结合模拟结果分析了在磨料浓度30%不同速度磨料水射流作用下岩石的损伤范围。其中磨料水射流采用SPH算法模拟,并通过修改关键字文件实现水与磨料两种不同组分,岩石采用H-J-C累计损伤模型。研究表明:岩石冲蚀坑首先成漏斗状,随着冲蚀坑不断加深,最终形成"V"形剖面和圆形截面组成的"子弹"体;损伤值由冲蚀坑沿径向方向向外急剧减少,岩石的损伤半径与冲蚀坑半径随着射流速度减小而减小,两者之比在1.8-2.2之间。计算结果与相关文献基本吻合,为研究磨料水射流破岩提供一种研究的方法。

The process of rock breaking with abrasive water jet （AWJ） is a nonlinear impact dynamic problem involved in lots of factors. Aiming at the complexity of the process and the mesh distortion problem in dealing with large deformation problems using the finite element method （ FEM）, the process of rock breaking with AWJ was simulated here based on the coupling algorithm of smoothed particle hydrodynamics （SPH） and FEM. Combined with the simulated results, the scope of rock damage process, AWJ was simulated under 30% concentration of AWJ at different speeds was analyzed. In the analysis SPH, the two different combinations of water and abrasive were gained by editing a keyword file, the rock was simulated with FEM using HJC cumulative damage model. The results showed that the rock crushing pit has a funnel shape firstly, with the erosion pit deepened, a ＂bullet＂ body is formed with a V-shaped cross- section and a circular cross-section ultimately; during this process, erosion radial outward direction ; besides, rock erosion damage damage decreases sharply from the pit in the radius and the erosion pit radius decreases with decrease in jet velocity, and the ratio between them is within 1.8 -2.2. The simulated results were basically consistent with those in the relevant references. The results provided a study method for rock breaking with AWJ.