臺灣博碩士論文加值系統

摘要
本論文結合Levy-Mises方程式體積不變與模具外型之空間向量夾角 ，推導出偏心管製程沖頭沖程與管端外型關係之理論式。為求理論式之驗證，本文在500kN油壓成形機上進行偏心管縮口試驗，模具之斜角為20°，工件為不鏽鋼管，沖程設定為50mm，從實驗與理論式的成形管件之管端外型、管端厚度之結果比較，驗證了理論式之正確性；同時，本論文整合黃金分割法理論與LS-DYNA有限元素分析，預測偏心管製程最佳化預成形切角，發現成形管件之管端外型更貼近實驗值。
在偏心管縮口管端斜角預測研究中，本論文整合黃金分割法理論與LS-DYNA有限元素分析，預測偏心管製程管端斜角，由LS-DYNA有
限元素分析，發現隨著沖程不同，管端角度變化也有所不同，且沖程大
小與成形角度變化呈線性函數，因此利用線性迴歸推導出管端成形角度
與沖程關係式，由實驗與有限元素分析之結果比較，當沖程達50mm時，
其管端口角度與線性迴歸關係式趨勢相同，故線性迴歸關係式有參考價
值，可做為工程實務上之應用。
關鍵字 : 偏心管縮口、最佳預成形、管端厚度分佈、黃金分割。

ABSTRACT
This thesis combines the Levy-Mises equation, constant volume law, and the space vector included angle to derive the theoretical expression between the punch stroke and tube end profile for the eccentric tube nosing process. As a verification of the theoretical expression, an eccentric tube nosing experiment was proceeded in the 500KN hydraulic forming machine. The die inclined angle equals20°. The workpiece is stainless tube. The punch stoke is 50 mm. From comparison of the results of the experimental tube end profile, tube end thickness between the experiment and theory, it proves the correctness of the theoretical expression. Meanwhile, this thesis integrated the golden section theory and LS-DYNA finite element simulation to predict the optimal preformed cutting angle in the eccentric tube nosing process. It is found that the formed tube end profile was more coincident with the experimental result.
In the study of prediction of the tube end inclined angle, this thesis integrated the golden section theory and LS-DYNA finite element simulation to predict the inclined angle for the eccentric tube nosing process. It is found that the tube end angle will be varied for the different strokes. And, the variation appears linear function between the punch stroke and formed tube end angle. Hence, a linear regression was used to derive the relation between the punch stroke and formed tube end angle. From the comparison of the results of the experiment and finite element analysis, it has the same tendency between formed tube end angle and linear regression expression after the punch stroke reaching 50 mm. Hence, the linear regression expression has the referable value to be the application in the engineering practicality.

Key words : Eccentric Tube Nosing、Optimal Preform、Tube End Thickness、Golden Section

目錄
摘要 I
ABSTRACT II
誌謝 IV
目錄 V
圖目錄 VIII
表目錄 VIII
第一章 緒論 1
1.1　前言 1
1.2　文獻回顧與研究動機 2
1.3　論文之構成 3
第二章 基本理論 5
2.1　偏心縮口理論 5
2.2　黃金分割法(Golden Section)理論 9
2.2.1偏心管縮口管端最佳預成形切角預測 11
2.2.2偏心管縮口管端斜角預測 13
第三章 偏心管縮口管製程有限元素分析步驟與實驗 17
3.1　偏心縮口管製程有限元素分析部分 17
3.1.1偏心縮口管製程分析流程 17
3.1.2偏心縮口製程建立模型與元素分割 18
3.1.3偏心縮口製程材料定義 20
3.1.4偏心縮口製程接觸設定 23
3.1.5偏心縮口邊界條件與負載設定 25
3.2　實驗部分 27
第四章 結果與討論 37
4.1　偏心縮口理論式之結果與討論 37
4.1.1沖程與負荷關係 37
4.1.2前向預測 37
4.1.3後向預測 38
4.2　黃金分割法求偏心管縮口管端最佳切角之結果與討論 45
4.3　黃金分割法求偏心管縮口管端斜角預測之結果與討論 51
第五章 結論與未來展望 60
5.1　結論 60
5.2　未來展望 61
參考文獻 62

圖目錄
圖2-1偏心圓錐空間向量夾角示意圖..............................................................5
圖2-2偏心管縮口製程示意圖..........................................................................6
圖2-3黃金分割法關係比例示意圖..................................................................9
圖2-4黃金分割法夾擊示意圖........................................................................10
圖2-4管端二次加工........................................................................................11
圖2-5管端預成形切角示意圖........................................................................12
圖2-6偏心管縮口管端最佳預成形切角預測流程........................................12
圖2-7偏心縮口管成形歷程............................................................................13
圖2-8臨界縮口比關係示意圖........................................................................14
圖2-9偏心縮口管端斜角接合........................................................................14
圖2-10偏心縮口管端斜角成形預測示意圖..................................................15
圖2-11偏心管縮口管端斜角預測流程..........................................................16
圖3-1管胚件網格模型示意圖........................................................................19
圖3-2偏心縮口模具網格模型示意圖............................................................19
圖3-3偏心縮口沖頭網格模型示意圖............................................................19
圖3-4剛體之參數設定圖................................................................................20
圖3-5指數型塑性材料之參數設定圖............................................................21
圖3-6 304不鏽鋼拉伸試驗與分析比較圖.....................................................22
圖3-7接觸類型之參數設定圖........................................................................24
圖3-8模擬之負載曲線圖................................................................................25
圖3-9邊界條件設定示意圖............................................................................26
圖3-10實驗設備示意圖..................................................................................29
圖3-11偏心縮口模具上座..............................................................................29
圖3-12偏心縮口模具下座..............................................................................30
圖3-13偏心縮口模具組合圖..........................................................................31
圖3-14沖頭尺寸..............................................................................................31
圖3-15沖頭模具..............................................................................................32
圖3-16管胚件上繪製基準線以利量測..........................................................32
圖3-17偏心縮口模具安裝..............................................................................33
圖3-18紅外線極限開關與雷射位移計..........................................................33
圖3-19塗抹固態潤滑劑..................................................................................34
圖3-20訊號擷取器..........................................................................................34
圖3-21螢幕顯示數據......................................................................................35
圖3-22量表校正管件同心度..........................................................................35
圖3-23量表測量管件每45°管端外型...........................................................36
圖4-1不同摩擦力下沖程與負荷之關係........................................................40
圖4-2前向預測管件成形側視圖....................................................................40
圖4-3前向預測成形後之管端厚度................................................................41
圖4-4前向預測von Mises 應力分佈圖.........................................................41
圖4-5前向預測塑性應變分佈圖....................................................................42
圖4-6理論式推導管端預成形圖....................................................................42
圖4-7後向預測管件成形側視圖....................................................................43
圖4-8後向預測成形後之管端厚度................................................................43
圖4-9後向預測von Mises 應力分佈圖.........................................................44
圖4-10後向預測塑性應變分佈圖..................................................................44
圖4-11目標函數尋求最佳切角示意圖..........................................................45
圖4-12目標函數與預成形切角最佳化關係圖..............................................46
圖4-13管胚件預成形切角..............................................................................47
圖4-14黃金分割法求偏心管縮口管端最佳切角成形管件..........................48
圖4-15黃金分割管件預成形最佳化成形後側視圖......................................48
圖4-16黃金分割管端最佳化成形後厚度......................................................49
圖4-17黃金分割管件預成形最佳化成形後von Mises 應力分佈圖...........50
圖4-18黃金分割管件預成形最佳化成形後塑性應變分佈圖......................50
圖4-19管端斜角預測與沖程關係示意圖......................................................51
圖4-20目標函數與預成形切角關係圖..........................................................52
圖4-21管胚件斜角預測切角..........................................................................53
圖4-22沖程為10mm時管端成形角度...........................................................54
圖4-23沖程為20mm時管端成形角度...........................................................54
圖4-24沖程為30mm時管端成形角度...........................................................55
圖4-25沖程為40mm時管端成形角度...........................................................55
圖4-26沖程為50mm時管端成形角度...........................................................56
圖4-27各沖程管端口角度關係圖..................................................................57
圖4-28實驗沖程35mm與50mm管端口角度比較圖....................................58
圖4-29偏心管縮口管端斜角預測沖程50mm von Mises 應力分佈圖........59
圖4-30偏心管縮口管端斜角預測沖程50mm之塑性應變分佈圖...............59

表目錄
表3-1各個接觸模式及接觸指令....................................................................23
表3-2管件尺寸及材料參數............................................................................27
表4-1 LS-DYNA有限元素分析各沖程與管端口角度關係表....................56
表4-2沖程與成形角度比較表........................................................................58

參考文獻
1.K.Manabe and H. Nishimura, “Forming loads in tube-flaring with conical punch-study on nosing and flaring of tubes V”, Journal of the Japan Society for Technology of Plasticity Vol. 24 , 264 (1983), pp. 47-51
2.K.Manabe and H.Nishimura, “Stress and strain distributions in tube-flaring with conical punch-study on nosing and flaring of tubes VI”, Journal of the Japan Society for Technology of Plasticity Vol. 24 , 266 (1983), pp. 276-282
3.K.Manabe and H. Nishimura, “Contact pressure distributions in nosing and flaring of tubes with conical tools”, Journal of Japan Institute of Light Metals, Vol. 34, 8 (1984) , pp. 439-445
4.B.P.P. Almeida, M.L. Alves, P.A.R. Rosa, A.G. Brito, P.A.F. Martins, “Expansion and reduction of thin-walled tubes using a die: Experimental and theoretical investigation”, International Journal of Machine Tools and Manufacture, Vol. 46, 12-13, (2006), pp. 1643-1652
5.B.P.P. Gouveia, M.L. Alves, P.A.R. Rosa, P.A.F. Martins, “Compression beading and nosing of thin-walled tubes using a die: Experimental and theoretical”, Internatienal Journal of Mechanics and Materials in Design Vol.3, 1 (2006), pp. 7-16
6.K. Kitazawa, “Criteria for outward curling of tubes”, ASME, Journal of Engineering for Industry. Vol. 115 , 4 (1993), pp. 466-471
7.K. Kitazawa, “Improvement in flaring limit of thin-walled circular tubes using precurling method”, JSME, Part C 62 594 (1996), pp. 773-778.
8.L. M. Alves, P. Vilaca, P.A.F. Martins, “Nosing of thin-wall hollow spheres using a die: Experimental and theoretical”, International Journal of Mechanicas and Materials in Design Vol.3 ,3(2006), pp. 337-346
9.J. Zhu, “A new approach to preform design in shell nosing”, Journal of Materials Processing Technology, 63 (1997), pp. 640-644
10.T. Kuboki, Y. Kimura, M. Murata, T. shimoda, “Tool design for suppressing fracture at the tip of tube after nosing with die”, VIII International Conference on Computational Plasticity, (2005), pp. 1-4
11.盧永華，“管端捲曲臨界沖頭圓弧半徑判斷準則之研究”，第二屆精密製造研討會，(2002)
12.Chin-Tarn Kwan, “An analysis of the ennentric nosing process of metal tubes”, Journal of Materials Processing Technology, Vol. 140, 1-3, (2003), pp. 530-534
13.Mahmoud Nemat-Alla, “On eccentric tube nosing”, Journal of Manufacturing Science and Engineering., Vol. 130, Issue 1, 011006, (2008), pp.1-8
14.黃偉澤, 管縮口製程之研究與實驗, 國立宜蘭大學機械與機電工程學系碩士論文, 2011
15.黃偉澤, 偏心管縮口製程之管端外型與厚度之研究, 精密機械與製造科技研討會論文集, 2011