45钢高速切削锯齿形切屑关键技术的有限元模拟

Abstract

有限元模拟是当前高速切削锯齿形切屑研究的一个重要手段，对揭示高速切削加工机理，优化切削参数具有重要意义。本文基于ABAQUS通用有限元软件，在45钢高速切削锯齿形切屑有限元模型基础上，开展几何模型、材料模型、摩擦模型和质量放大等有限元模拟关键技术的研究。研究结果表明：在进行锯齿形切屑有限元模拟几何建模时，采用45˚锐角平行四边形的工件几何模型能够较好地克服网格畸变的影响，获得更好的模拟结果；材料模型参数对模拟结果影响很大，采用不同实验方法和实验条件获得的本构关系时模拟结果差别很大；摩擦系数变化对模拟结果也有很大影响，对45钢来说，摩擦系数取0.3时模拟结果较好；质量放大对锯齿形切屑有限元模拟有效，合适的质量放大系数可以在确保模拟结果准确的条件下大量节省时间成本。 The finite element simulation is one of the important methods for the study of serrated chip in high speed cutting. It is significant for revealing the mechanism of high speed machining and optimizing the cutting parameters. In this paper, based on the general finite element software ABAQUS and the finite element model of serrated chip of 45 steel in high speed cutting, the critical technologies, such as the geometry model, material model, friction model and mass scaling are investigated. The results show that: In the process of building the finite element geometry model of serrated chip, using the work-piece geometry model with 45˚ angle can better overcome the influence of grid distortion and obtain a better simulation result. The parameters of material model have great influence on the simulation results. The simulation results using different constitutive relationship obtained from different experiment method and conditions have great difference. The friction coefficient also has great influence on the simulation results. For the 45 steel, when the friction coefficient is taken as 0.3, the simulation result is better. The mass scaling is valid for the finite element simulation of serrated chip. An appropriate mass scaling coefficient can be guaranteed to save the time cost in the condition of obtaining the accuracy simulation results.