簡易檢索 / 詳目顯示

回結果列表
研究生： 吳孟賢
MENG-HSIEN WU
論文名稱： 不同厚度與晶粒尺寸之比值對微引伸成形之影響
Influence of Different Ratios of Thickness and Grain Size on Micro Drawing Process
指導教授： 黃佑民
YOU-MIN HUANG
口試委員: 向四海
SU-HAI HSIANG
陳聰嘉
Tsung-Chia Chen
學位類別： 碩士
Master
系所名稱： 工程學院 - 機械工程系
Department of Mechanical Engineering
論文出版年： 2010
畢業學年度： 98
語文別： 中文
論文頁數： 91
中文關鍵詞： 微引伸 、厚度與晶粒尺寸之比值 、尺寸效應
外文關鍵詞： micro drawing, ratios of thickness to grain size, size effect
相關次數： 點閱：217  下載：1 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 本文採用Prandtl-Reuss塑流法則與von Mises之降伏條件，並以有限變形理論及updated Lagrangian formulation (ULF)之觀念建立一增量型彈塑性大變形三維有限元素分析程式。利用四邊形四節點之退化殼元素(degenerated shell element)所推導之形狀函數耦合入剛性矩陣，組成三維有限元素之分析模式，並且使用廣義 法則處理金屬板材在成形時，包含元素之降伏判斷、最大容許應變增量、最大容許旋轉增量、料片與模具間節點之接觸與分離判斷等問題。
    本文主要以純銅箔為研究對象，經過不同溫度的再結晶退火，在相同厚度下，不同晶粒大小時，其厚度與晶粒尺寸之比值對微引伸成形性之影響。並藉由數值模擬分析所得到的資料，如沖頭之負荷與位移關係、應力與應變分佈等。最後將實驗結果與數值模擬結果做一比較，驗證在此一厚度時有限元素分析程式之準確性與適用性。

    In this paper, a methodology for formulating an elasto-plastic three-dimensional finite element model is developed to simulate sheet metal forming process. It is based on Prandtl-Reuss flow rule and von Mises yield criterion respectively and associated with an updated Lagrangian formulation. The shape function derived from a four-node quadrilateral degenerated shell element is associated into the stiffness matrix to constitute the finite element model. An extended algorithm is proposed to formulate the boundary condition, such as nodal penetration and separation, strain increment and rotation increment, and altered elasto-plastic state of material.
    The research object in this paper is mainly about pure copper recrystallization annealing at different temperatures based on the same thickness which will create different grain sizes and the influence of ratios of thickness to grain size in micro drawing. Also, the simulation results include the relationship between punch load and punch stroke, and the distribution of stress and strain. Finally, the experimental results and the simulation results will be compared, and verify the accuracy and applicability in the finite element analysis program at specific thickness.

    摘要 I ABSTRACT II 誌謝 III 目錄 IV 符號索引 VIII 圖表索引 XIII 第一章 緒論 1 1.1 前言 1 1.2 文獻回顧 2 1.2.1 尺寸效應 2 1.2.2 尺寸效應對塑流應力的影響 3 1.2.3 相似理論 5 1.2.4 表面塑性層效對微成形的影響 7 1.2.5 試片厚度及晶粒大小之比值對塑流應力之影響 8 1.2.6 摩擦對微成形試驗之影響 9 1.3 研究動機與目的 10 1.4 論文架構 11 第二章 基本理論 12 2.1 有限元素法之發展 12 2.2 基本假設 15 2.3 有限變形之應變與應變率 15 2.4 有限變形之應力與應力率 16 2.5 有限變形之update Lagrangian formulation 18 2.6 材料之彈塑性構成關係式 22 第三章 金屬板材有限元素分析 26 3.1 簡介 26 3.2 虛功原理的離散化 29 3.3 退化殼元素(Degenerated Shell Element) 30 3.4 不同積分法則推導退化殼元素之剛性矩陣 32 3.5 摩擦處理 34 3.6 廣義 法之增量步驟的計算 38 3.7 三維曲度修正方程式 41 3.8 除荷之設定 42 3.9 數值分析之流程摩擦處理 42 第四章 實驗方法 45 4.1 實驗材料之選取與實驗流程規劃 45 4.2 熱處理與金相實驗 46 4.2.1 熱處理 46 4.2.2 熱處理設備與實驗步驟 46 4.2.3 金相實驗 48 4.2.4 平均晶粒大小之計算方法 49 4.2.5 金相實驗結果 52 4.3 拉伸試驗 57 4.3.1 拉伸試驗之設備 57 4.3.2 拉伸試驗之試片製作 59 4.3.3 拉伸實驗步驟 59 4.3.4 拉伸實驗之結果 60 4.4 微引伸成形試驗 63 4.4.1 模具設計與介紹 63 第五章 實驗結果 65 5.1 前言 65 5.2 微小圓杯引伸之數值分析 65 5.3 數值分析與實驗結果之比較 68 5.3.1 模擬之變形歷程 68 5.3.2 模穴圓角與模穴間隙對成形之影響 69 5.3.3 沖頭負荷與衝程關係 74 5.4 t/d值對成形性之影響 76 第六章 結論 86 6.1 結論 86 6.2 未來展望 87 參考文獻 88 作者簡介 91

    1.M. Gerier, F. Vollertsen and R. Kals, “Fundamentals on manufacturing of sheet metal microparts,” Annals of the CIRP, Vol. 45, pp.277-282. (1996).
    2.M. Geiger and M. Kleiner, R. Eckstein, N. Tiesler and U. Engel,“Microforming,” CIRP Annals–Manufacturing Technology, Vol. 50,pp.445-462（2001）.
    3.A. Messner, U. Engel, R.Kals and F. Vollertsen, “Size Effect in The FE-Simulation of Micro-Forming Processes,” Journal of Materials Processing Technology, Vol. 45, pp.371-376 (1994)
    4.M. Geiger, R. Eckstein, “Microforming-Advanced Technology of Plasticity. ” Proceedings of the 7th ICTP. pp.327-338. (2002).
    5.J. F. Michel and P. Picart, “Size Effects on The Constitutive Behaviour forBrass in Sheet Metal Forming,” Journal of Materials Processing Technology, Vol. 141, pp.439-446 (2003).
    6.L. V. Raulea, A. M. Goijaerts, L. E. Govaert and F. P. T. Baaijens, “Size Effects in The Processing of Thin Metal Sheets,” Journal of Materials- 106 -Processing Technology, Vol. 115, pp.44-48 (2001).
    7.T. A. Kals and R. Eckstein, “Miniaturization in Sheet Metal Working,” Journal of Materials Processing Technology ,Vol. 103,pp.95-101 (2000).
    8.Yasunori Saotome, Kaname Yasuda and Hiroshi Kaga, “Microdeep Drawability of Very Thin Sheet Steels,” Journal of Materials Processing Technology, Vol. 113,pp.641-647 (2001)
    9.U. Engel and R. Eckstein, “ Microforming ─ From Basic Research to Its Realization,” Journal of Materials Processing Technology, Vol. 125-126, pp.35-44（2002）.
    10.R. Kals, F. Vollertsen and M. Geiger, “Scaling Effects in Sheet Metal Forming,” Proceedings of the Fourth International Conference on Sheet Metal ( SheMet ), Vol. 2, pp.65-75（1999）
    11.S. Miyazaki, H. Fujita and H. Hiraoka, “Effect of specimen size on the flow stress of rod specimens of polycrystalline Cu-Al alloy,” Scripta Metallurgica, Vol. 13, pp.447 – 449 (1979).
    12.P. J. M. Janssen, Th. H. de Keijser and M. G. D. Geers, “An experimental assessment of grain size effects in the uniaxial straining of thin Al sheet with a few grains across the thickness, ” Materials Science and Engineering, Vol. A419, pp. 238 – 248 (2006).
    13.N. Tiesler and U. Engel, “Microforming -Effects of Miniaturization , ”Proceedings of The 8th International Conference on Metal Forming,pp.355-360 (2000).
    14.Y. Yamada, N. Yoshimura and T. Sakurai, “Plastic Stress Strain Matrix and Its Application for the Solution of Elastic-Plastic Problems by Finite Element Method ,” International Journal of Mechanical Sciences, Vol. 10, pp. 343-354 (1968).
    15.C. Zienkiewicz, S. Valliappan and I. P. King, “Elasto-Plastic Solution of Engineering Problems , Initial-Stress , Finite Element Approach ,” International Journal of Numerical Methods for Engineering, Vol. 1, pp.75-100 (1969).
    16.H. D. Hibbit, P. V. Marcal and J. R. Rice, “A Finite Element Formulation for Problem of Large Strain and Large Displacement,” International Journal of Solids and Structures, Vol. 6, pp.1069-1086 (1970).
    17.R. M. McMeeking and J. R. Rice, “Finite-Element Formulation for Problems of Large Elastic-Plastic Deformation,” International Journal of Solids and Structures, Vol. 11, pp.601-616 (1975).
    18.Y. Hayashi and M. Takagi, “Control of Side Wall Curl in Draw Bending of High Strength Steel Sheets,” Proceeding of Advance Technology of Plasticity, Vol. 1, pp.735-740 (1984).
    19.A. Makinouchi, “Finite Element Modeling of Draw-Bending Process of Sheet Metal,” Proceeding of the NUMIFORM’86 Conference, Gothenburg, Vol. 25-29, August, pp.327-332 (1986).
    20.J. C. Nagtegaal and N. Rebelo, “On the Development of A General Purpose Finite Element Program for Analysis of Forming Process,” Int. J. Num. Meth. Engng. , Vol. 25, pp.113-131 (1988).
    21.A. Makinouchi, Y. Shirataki, S. D. Liu and Y. Nagai, “Generalization of Tool-Work Contact Conditions for Elasto-Plastic Analysis of Forming Process,” Advanced Technology of Plasticity, Vol. 3, pp.1161-1166 (1990).
    22.Y. M. Huang, H. Takizawa, A. Makinouchi and T. Nakagawa,“Elastic-Plastic Analysis of V-Bending Process,” Spring Proceeding of Plastic Working, Cho-Fu, Tokyo, pp.275-278 (1989).
    23.A. Makinouchi and M. Kawka, “Process simulation in sheet metalforming,” Journal of Materials Processing Technology, Vol.46, pp.291-307 (1994).
    24.M. Kawka, and A. Makinouchi, , “Shell-element formulation in the static explicit FEM code for the simulation of sheet stamping,”Journal of Materials Processing Technology, Vol.50,pp.105-115 (1995).

    QR CODE