淬硬钢材料高速切削过程的有限元仿真

论文编号:JX1513  论文字数:18427.页数:40

摘   要
 
 在金属切削加工中，对切削过程的研究有着重要的意义。已有的研究表明，数值方法是研究切削加工过程的一种有效手段。为此，本文采用三维热力耦合有限元模拟技术，对金属切削过程进行了系统的研究。
 本文首先系统分析了金属切削过程的有限元建模理论，建立了金属切削三维热力耦合刚粘塑性有限元模型，确定了材料模型、切屑分离准则、网格划分、接触摩擦模型、磨损模型和边界条件等。基于 DEFORM-3D 软件平台，成功地模拟了金属切削加工过程。揭示了等效应变、温度场、刀具磨损的分布规律。模拟结果表明该模型是可靠的。
 研究揭示了主要工艺参数对切屑变形、切削力、切削温度、刀具磨损的影响规律。通过与理论分析的比较，验证了数值模拟的可行性，为工艺参数优化、切削质量控制及刀具设计提供了依据。
 
关键词：切削,三维数值模拟,刚粘塑性有限元，热力耦合

ABSTRACT
 In the field of metal cutting, it has an important significance to the investigation of the cutting process. The existed researches show that it is effective to investigate cutting process using numerical method. Therefore, in this paper, a systematic investigation on metal cutting process has been carried out using 3D coupled thermal-mechanical FEM numerical simulation.
 In this paper, the finite element models of metal cutting were first discussed systemically. A 3D finite element model under coupled thermo-mechanical effects of metal cutting has been developed based on rigid-viscoplastic FEM, and some key technologies have been confirmed, including material model, chip separation criteria, meshing, the contact friction model, abrasion model, contact boundary, etc. Based on the platform of finite element software DEFORM-3D, the processes of metal cutting were simulated successfully. The laws of distribution have been disclosed for equivalent strain field, temperature field and tool wear. The model has been validated by simulation results to be reliable.
 The influence of main process parameters on chip distortion, cutting force, cutting temperature and tool wear have been disclosed. By comparing with the theoretical analysis, the feasibility of the numerical simulation was validated, the obtained results may provide a guide to optimizations of process parameters, control of the cutting quality and tool design.
 KEY WORDS: Machining, Three dimensional numerical simulation, rigid- viscoplastic FEM,thermal-mechanical

 第1章 绪论 5
 1.1 引言 5
 1.2 国内外研究综述 5
 1.2.1 发展情况 5
 1.2.2 有限元分析法研究高速切削 6
 1.3 关于Deform-3D软件的介绍 6
 1.4 淬硬钢高速切削的特点 7
 1.5 难加工材料高速切削的展望 7
 1.6 本文研究的主要内容 7
 第2章 金属高速切削理论 9
 2.1 金属切削基本理论 9
 2.1.1 金属切削变形理论 9
 2.1.2 热力耦合理论 9
 2.2 车削过程分析 9
 2.2.1 车削过程的塑性变形 9
 2.2.2 切削力 10
 2.3 高速金属切削的切削温度 12
 第3章 金属切削过程仿真的有限元基础理论 13
 3.1 有限单元分析方法概述 13
 3.2 金属塑性成形有限元概述 15
 3.2.1 弹（粘）塑性有限元法 15
 3.2.2 刚（粘）塑性有限元法 16
 第4章 淬硬钢34CrNiMo6的三维有限元模型建立 17
 4.1 Deform-3D的建模理论 17
 4.1.1 Deform仿真的顺序 17
 4.2 刀具的模型建立 18
 4.3 工件的本构关系 18
 4.3.1 34CrNiMo6的本构关系 19
 4.4 刀具与工件的网格划分 20
 4.5 摩擦模型的建立及接触问题的处理 22
 4.5.1 摩擦模型的建立 22
 4.5.2 接触问题的处理 23
 4.6 刀具磨损模型 23
 4.7 热力耦合分析技术及传热边界条件 24
 第5章 34CrNiMo6的切削实验 25
 5.1 34CrNiMo6的材料属性 25
 5.2 刀具的材料属性 26
 5.3 车削的实验数据 26
 5.3.1 各组切削实验数据 26
 5.4 车削实验与仿真结果的试验验证 28
 第6章 切削模型计算结果及分析 30
 6.1 切削过程的模拟结果 30
 6.1.1 切屑的形成过程 30
 6.1.2 主切削力的提取 31
 6.1.3 切削应力分布 32
 6.1.4 切削应变的分布 32
 6.1.5 温度的分布 33
 6.2 切削参数对主切削力的影响 33
 6.2.1 不同切削速度对主切削力的影响 33
 6.2.2 进给量对主切削力的影响 34
 6.2.3 背吃刀量对主切削力的影响 34
 第7章 结论 37
 参考文献 39
 致谢 40

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