臺灣博碩士論文加值系統

隨著日益嚴重的全球暖化與逐漸被重視的環保意識，以先進高強度鋼作為汽車結構件的材料已漸漸成為主流，其高強度可使使汽車結構件以較薄的厚度達到相同之強度，同時兼顧輕量化與安全性。但隨著鋼板強度提升，沖壓成形後之回彈缺陷亦更加明顯，常見之回彈缺陷有側壁外開、側壁捲曲與扭曲，其中扭曲為最複雜之回彈缺陷，本研究嘗試探討板金沖壓成形當中之扭曲回彈缺陷。
汽車結構件當中以A柱最容易產生扭曲之回彈缺陷，本研究歸納A柱之特徵造型參數，建立仿A柱之混合斷面基礎載具，以專業板金沖壓模擬軟體PAM-STAMP進行混合斷面基礎載具之成形模擬，模擬使用之材料為980級先進高強度鋼。首先針對不同造型參數進行成形性分析，探討各造型參數對於破裂與皺褶之影響，結果可以做為A柱造型設計之參考。接著模擬不同造型參數對扭曲影響，透過不同造型參數之混合斷面基礎載具成形後之板材應力分析，探討扭曲機制。透過常見之回彈改善策略如壓料力、阻料條與模面補償進行扭曲之改善，其中本研究找出扭曲之模面補償方式，解決扭曲之模面補償後無法沖壓的問題，同時改善扭曲之效果亦相當顯著，扭曲量由9度改善至1.5度。研究最後進行混合斷面基礎載具之模具設計。

As the global warming becomes worse and the environmental consciousness rises, AHSS has been widely used as the material of automobile structural parts. However, as the strength of steels increases, stamping defects such as sidewall curl and distortion become worse. This study investigates the distortion in sheet metal forming.
A-pillar is an automobile structural part. Among all automobile structural parts, A-pillar is most likely to be distorted. This study induces the geometric parameters of A-pillar. This study also establishes a model for curved hat channel which has similar geometry with the A-pillar and uses PAM-STAMP to simulate the stamping process with the established model. This study investigates the formability influenced by different geometric parameters. The result can be the reference for A-pillar design. Next, this study simulates the distortion defects influenced by different geometric parameters. By studying the stress distribution on different cases, the mechanism of distortion can be discussed. Furthermore, strategies, like drawbead and die compensation, are used to reduce distortion. This study proposes two die compensation methods for distortion which solve the problem that punch have no space to stamp after compensation. The result in reducing distortion is significant, from 9 degrees to 1.5 degrees. At last, a curved hat channel die has been designed.

目錄 I
圖目錄 IV
表目錄 VIII
第一章緒論 1
1.1前言與研究背景 1
1.2研究動機與目的 5
1.3文獻回顧 7
1.4研究方法與步驟 11
1.5論文總覽 13
第二章混合斷面基礎載具之建立 14
2.1 A柱簡介與造型參數歸納 15
2.2 簡化A柱之混合斷面基礎載具建立 16
2.3 收斂性測試 18
2.3.1 板材網格尺寸 19
2.3.2 厚度方向積分點數 20
2.3.3 沖壓速度 21
2.3.4 最大自適應網格細化度 22
2.3.5 收斂性測試結果 23
2.4 混合斷面基礎載具不同造型參數之成形性分析 24
2.4.1 沖深 25
2.4.2 U型區長 27
2.4.3 V型區長 29
2.4.4 轉折角度 31
2.4.5 母模R 33
2.4.6 沖頭R 35
2.4.7 造型參數對成形性影響整理 37
第三章混合斷面基礎載具扭曲之探討 38
3.1 不同造型參數對扭曲之影響 38
3.1.1 沖深 39
3.1.2 U型區長 39
3.1.3 V型區長 40
3.1.4 轉折角度 41
3.1.5 母模R 42
3.1.6 沖頭R 43
3.1.7 造型參數對扭曲影響之綜合整理 44
3.2 扭曲之可能機制討論 44
第四章混合斷面基礎載具扭曲改善之探討 49
4.1 壓料力 49
4.2 阻料條 53
4.2.1 全區阻料條 54
4.2.2 局部阻料條 57
4.3模面補償 61
4.3.1 單邊補償 62
4.3.2 雙邊補償 64
第五章混合斷面基礎載具模具設計 67
5.1 開模模具之設計 69
5.1.1 上模 69
5.1.2 壓料板 71
5.1.3 下模 72
第六章結論與未來展望 75
6.1結論 75
6.2未來展望 76
參考文獻 77
作者簡歷 80

[1]http://www.boronextrication.com/2009/12/03/more-uhss-and-ahss-in-the-future/(取自2017.7.15)
[2]http://www.worldautosteel.org. (取自2017.7.15)
[3]洪英治, “先進高強度鋼板沖壓成形包辛格效應之研究,” 國立台灣大學機械工程學研究所碩士論文, 2011.
[4]Nasser, A. Yadav, P. Pathak and, T. Altan, “Determination of the flow stress of five AHSS sheet materials (DP 600, DP 780, DP 780-CR, DP 780-HY and TRIP 780) using the uniaxial tensile and the biaxial Viscous Pressure Bulge (VPB) tests,”Journal of Materails Processing Technology, vol. 210, pp. 429-436, 2010.
[5]R. Hill, “Constitutive modeling of orthotropic plasticity in sheet metals”, Journal of the Mechanics and Physics of Solids, Vol. 38, pp. 405-417, 1990.
[6]R. Hill, “A theoretical perspective on in-plane forming of sheet metal”, Journal of the Mechanics and Physics of Solids, Vol. 39, No. 2, pp. 295-307, 1991.
[7]R. Hill, “A user-friendly theory of orthotropic plasticity in sheet metals”, International Journal of Mechanical Sciences, Vol. 35, No. 1, pp. 19-25, 1993.
[8]R. Hill, S. S. Hecker, M. G. Stout, “An investigation of plastic flow and differential work hardening in orthotropic brass tubes under fluid pressure and axial load”, International Journal of Solids Structure, Vol. 31, No. 21, pp. 2999-3021, 1994.
[9]L. Wang and T. C. Lee, “The effect of yield criteria on the forming limit curve prediction and the deep drawing process simulation,” International Journal of Machine Tools and Manufacture, vol. 46, pp. 988-995, 2006.
[10]D. C. Ahn, J. W. Yoon and, K. Y. Kim, “Modeling of anisotropic plastic behavior of ferritic stainless steel sheet,” International Journal of Mechanical Sciences, vol. 51, pp. 718-725, 2009.
[11]顏暄明, “雙軸拉伸試驗夾治具機構與試片形狀之優化設計,” 國立台灣大學機械工程研究所碩士論文, 2015.
[12]C. Gomes, O. Onipede and, M. Lovell, “Investigation of springback in high strength anisotropic steels,” Journal of Materials Processing Technology, vol. 159, pp. 91-98, 2004.
[13]J.T. Gau and G. L. Kinzel, “A new model for springback prediction in which the Bauschinger effect is considered,” International journal of mechanical sciences, vol. 43, pp. 1813-1832, 2001.
[14]F. Yoshida, T. Uemori, and K. Fujiwara, “Elastic-plastic behavior of steel sheet under in-plane cyclic tension-compression at large strain,” International Journal of Plasticity, Vol. 18, pp. 633–659,2002.
[15]F. Yoshida and T. Uemori, “A model of large-strain cyclic plasticity describing the Bauschinger effect and workhardening stagnation,” International Journal of Plasticity, Vol. 18, pp. 661–686, 2002.
[16]S. D. D. M. K. Dr. Stuart Keeler, M.Sc., “Advanced High-Strength Steels Application Guidelines V5,” 2014
[17]蘇昱竹, “先進高強度鋼板沖壓成形回彈現象之研究,” 國立台灣大學機械工程研究所碩士論文, 2007.
[18]王孟捷, “壓料力改善先進高強度鋼側壁捲曲之研究,” 國立台灣大學機械工程研究所碩士論文, 2016.
[19]葉昱廷, “可調式阻料條改善側壁捲曲之研究,” 國立台灣大學機械工程研究所碩士論文, 2016.
[20]X. A. Yang, “A die design method for springback compensation based on displacement adjustment “ International Journal of Mechanical Sciences ,
[21]Dezelak, M.,Stepisnik A.,Pahole I.and Ficko M., “Evaluation of Twist Springback Prediction After an AHSS Forming Process.” International Journal of Simulation Modelling 13(2): 171-182. 2014
[22]X. Xue, J. Liao, G. Vuncze and F. Barlat, "Twist springback characteristics of dual-phase steel sheet after non-axisymmetric deep drawing." International Journal of Material Forming,2015
[23]X. Xue, J. Liao, G. Vuncze, J. Sousa and F. Barlat ”Modeling and sensitivity analysis of twist springback in deep drawing of dual-phase steel, International Journal of Materials and Design , 90 ,pp. 204-217, 2016.
[24]H. Li, G Sun, G. Li, Z. Gong and D. Liu, "On twist springback in advanced high-strength steels." Materials & Design vol.32 pp: 3272-3279,2011.
[25]魏華佐,”先進高強度鋼板沖壓成形扭曲現象之研究” 國立台灣大學機械工程研究所碩士論文, 2010.
[26]周暐宬,”高強度汽車結構件沖壓成形扭曲現象分析,” 國立台灣大學機械工程研究所碩士論文, 2010.
[27]陳冠杰,”高強度汽車結構件造型參數對成形缺陷之研究,” 國立台灣大學機械工程研究所碩士論文, 2014.