先進高強度鋼板沖壓成形回彈現象之研究

A Study of Springback in the Sheet Metal Forming of Advanced High Strength Steel

蘇昱竹(Yuh-Chu Su)

指導教授 ： 陳復國

國立臺灣大學/工學院/機械工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.03193

摘要

為了減少溫室氣體的排放，並提昇燃油效率，汽車減重為各大汽車廠努力的目標，而為達到此目標，各大車廠紛紛採用高強度鋼板來取代傳統鋼板，因為高強度鋼板相較於傳統鋼板具有高強度之特性，能夠藉由減少汽車板金件板厚來達到減重的目的。然而在沖壓成形中，回彈為無法避免的問題，且隨著使用之材料的強度愈高，回彈現象愈嚴重，故本研究採用V型彎曲、U型彎曲以及U形帽狀（U-hat）成形實驗來了解回彈之特性，並選用270級軟鋼、590R、590Y高強度鋼板來了解高強度鋼板與傳統鋼板在回彈現象的差異性。在製程參數上探討沖頭圓角、母模圓角、壓料力以及厚度對於回彈之影響性。並利用有限元素法軟體模擬高強度鋼板回彈之行為，驗證CAE模擬回彈之正確性。另外，收集、歸納與整理改善回彈之方法。最後，進行業界實際板金件之回彈模擬，探討相關製程之回彈行為。

關鍵字

高強度鋼板 ； 沖壓成形 ； 回彈現象 ； 彎曲成形 ； 製程參數 ； 有限元素法 ； CAE

並列摘要

In order to mitigate the greenhouse effect and promotion of fuel-efficient, how to reduce the weight of vehicle has became the new goal for the automotive manufactures. For this reason, automotive manufactures replace conventional steel sheets with high strength steel sheets to reduce the thickness and weight of sheets used in vehicle. Springback is the severe problem in the sheet metal forming process, and is getting serious with adopting higher strength materials. In this study, we proceeded V-bending, U-bending and U-hat forming experiment to realize the characteristics of springback, and compared the experiment results of three specimens, 270 level mild steel and 590R, 590Y high strength steel, to understand the differences of springback between high strength steel and conventional steel. Furthermore, we discussed the influences of the four parameters, punch radius, die radius, blank holder force, and thickness, on the springback experiments. Analyzing springback behavior of high strength steel by using the software of the finite element method to validating simulation. Besides, the methods of diminishing springback were collected. Finally, springback simulations of industrial sheet metal case were conducted to discussing springback behavior of correlative process.

並列關鍵字

high strength steel ； stamping forming ； springback ； bending process ； process parameter ； finite element method ； CAE

參考文獻

[1] M. Samuel, Experimental and numerical prediction of springback and side wall curl in U-bendings of anisotropic sheet metals, Journal of Materials Processing Technology, 105(3): pp.382-393, 2000.

[5] 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, 43(8): pp.1813-1832, 2001.

[6] Lingbeek, The development of a finite elements based springback compensation tool for sheet metal products, Journal of Materials Processing Technology, 169, pp.115-125, 2005.

[9] N. Asnafi, On springback of double-curved autobody panels, International Journal of Mechanical Sciences, 43(1): pp.5-37, 2001.

[10] Q.V. Bui, L. Papeleux, and J.P. Ponthot, Numerical simulation of springback using enhanced assumed strain elements. Journal of Materials Processing Technology, 153-154: pp.314-318, 2004.