锻压技术

板材拉伸破裂厚度分布及成形极限预测

英文标题：Experimental and numerical investigation on sheet metal forming limit prediction with thickness related criteria

作者：刘长丽周贤宾陈劼实

单位：北京航空航天大学机械工程及自动化学院北京航空航天大学机械工程及自动化学院北京航空航天大学机械工程及自动化学院北京100083 北京100083 北京100083

分类号：TG386

出版年,卷(期):页码：2006,31(5):147-150

摘要：

对ST14钢板单向拉伸试件断口处的厚度进行了测量,获得其厚度分布和厚度梯度分布。从厚度变化和厚度梯度分布变化的角度对分散性失稳区和集中失稳区进行划分;分析了厚度分布非对称现象的成因。采用数值模拟的方法,分别得出了以失稳减薄率和破裂减薄率作为判据的成形极限图,经过与实验成形极限图的比较,失稳减薄率判更适于预测拉-压区成形极限,破裂减薄率能够对整个成形极限图范围内的曲线变化趋势进行预测。

Thickness distribution and thickness gradient distribution of sheet metal ST14 tensile samples are gained by experiment,thus the onset of necking can be determined by these two types of distributions.Certain sample's thickness distribution on both sides of facture is unsymmetrical.The reason for this phenomenon is analyzed.FLD(using) single steadily deforming thickness thinning criterion and FLD using fracture thickness thinning criterion are determined.Comparing with experimental FLD,steadily deforming thickness thinning criterion has a better conformability for the left side of FLD while fracture thickness thinning criterion can predict the shape of the curve for the entire range.

基金项目：

高等学校博士学科点专项科研基金资助项目(20040006022)

参考文献：

[1]Swift H W.Plastic instability under plane stress[J].J.Mech.Phys.Solids,1952,(1):1 18.
[2]Hill R.On discontinuous plastic states with special reference tolocalized neckingin thin sheets[J].J.Mech.Phys.Solids,1952,(1):19 31.
[3]Marciniak Z,Kuczynski K.Li mit strain in the processes ofstretch-forming sheet metal[J].International Journal ofMechanical Sciences,1967,(9):609 620.
[4]Kumar S,Date P P,Naresi mhan K.A newcriterion to pre-dict necking failure under biaxial stretching,[J].Journal ofMaterials Processing Technology,1994,l45:533 573.
[5]Ozturk Fahrettin,Lee Daeyong.Analysis of formingli mits u-sing ductile fracture criteria[J].Journal of Materials Process-ing Technology,2004,147(3):397 404.

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