淬硬鋼材料高速切削過程的有限元仿真

論文編號:JX1513  論文字數:18427.頁數:40

摘   要
 
 在金屬切削加工中，對切削過程的研究有著重要的意義。已有的研究表明，數值方法是研究切削加工過程的一種有效手段。為此，本文采用三維熱力耦合有限元模擬技術，對金屬切削過程進行了系統的研究。
 本文首先系統分析了金屬切削過程的有限元建模理論，建立了金屬切削三維熱力耦合剛粘塑性有限元模型，確定了材料模型、切屑分離準則、網格劃分、接觸摩擦模型、磨損模型和邊界條件等。基于 DEFORM-3D 軟件平臺，成功地模擬了金屬切削加工過程。揭示了等效應變、溫度場、刀具磨損的分布規律。模擬結果表明該模型是可靠的。
 研究揭示了主要工藝參數對切屑變形、切削力、切削溫度、刀具磨損的影響規律。通過與理論分析的比較，驗證了數值模擬的可行性，為工藝參數優化、切削質量控制及刀具設計提供了依據。
 
關鍵詞：切削,三維數值模擬,剛粘塑性有限元，熱力耦合

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 緒論 5
 1.1 引言 5
 1.2 國內外研究綜述 5
 1.2.1 發展情況 5
 1.2.2 有限元分析法研究高速切削 6
 1.3 關于Deform-3D軟件的介紹 6
 1.4 淬硬鋼高速切削的特點 7
 1.5 難加工材料高速切削的展望 7
 1.6 本文研究的主要內容 7
 第2章 金屬高速切削理論 9
 2.1 金屬切削基本理論 9
 2.1.1 金屬切削變形理論 9
 2.1.2 熱力耦合理論 9
 2.2 車削過程分析 9
 2.2.1 車削過程的塑性變形 9
 2.2.2 切削力 10
 2.3 高速金屬切削的切削溫度 12
 第3章 金屬切削過程仿真的有限元基礎理論 13
 3.1 有限單元分析方法概述 13
 3.2 金屬塑性成形有限元概述 15
 3.2.1 彈（粘）塑性有限元法 15
 3.2.2 剛（粘）塑性有限元法 16
 第4章 淬硬鋼34CrNiMo6的三維有限元模型建立 17
 4.1 Deform-3D的建模理論 17
 4.1.1 Deform仿真的順序 17
 4.2 刀具的模型建立 18
 4.3 工件的本構關系 18
 4.3.1 34CrNiMo6的本構關系 19
 4.4 刀具與工件的網格劃分 20
 4.5 摩擦模型的建立及接觸問題的處理 22
 4.5.1 摩擦模型的建立 22
 4.5.2 接觸問題的處理 23
 4.6 刀具磨損模型 23
 4.7 熱力耦合分析技術及傳熱邊界條件 24
 第5章 34CrNiMo6的切削實驗 25
 5.1 34CrNiMo6的材料屬性 25
 5.2 刀具的材料屬性 26
 5.3 車削的實驗數據 26
 5.3.1 各組切削實驗數據 26
 5.4 車削實驗與仿真結果的試驗驗證 28
 第6章 切削模型計算結果及分析 30
 6.1 切削過程的模擬結果 30
 6.1.1 切屑的形成過程 30
 6.1.2 主切削力的提取 31
 6.1.3 切削應力分布 32
 6.1.4 切削應變的分布 32
 6.1.5 溫度的分布 33
 6.2 切削參數對主切削力的影響 33
 6.2.1 不同切削速度對主切削力的影響 33
 6.2.2 進給量對主切削力的影響 34
 6.2.3 背吃刀量對主切削力的影響 34
 第7章 結論 37
 參考文獻 39
 致謝 40