摘要
板料卸载后回弹变形对覆盖件的精度影响很大,研究回弹过程的影响因素对于板料成形过程的模具设计非常重要.基于NUMISHEET’93的U形弯曲标准考题,考虑板材与模具间的接触演变过程,建立了一个新的有限元模型来预测回弹.模拟中板材卸载过程采用模具反向运动方法.模拟结果与NUMISHEET’93的试验结果比较表明了模型的正确性和可行性.对不同的回弹影响因素研究发现,压边力、模具凹模圆角和板材厚度对回弹结果有较大影响.随着压边力的增加回弹迅速降低,但是同时板材的最小厚度也下降.板料厚度对回弹的影响大于压边力.
Springback during unloading affects the dimensional accuracy of sheet metal parts. The purpose of this paper is to study the factors influencing springback. A new finite element model based on U - bending benchmark of NUMISHEET＇ 93 has been proposed to predict springback with contact evolution between the sheet and dies. Sheet unloading process is simulated by the tools＇ reverse motion. The simulation results agree well with experimental data of NUMISHEET＇ 93. The effects of several key factors such as blank holding force （BHF） , fillets of the die and thickness of sheet are investigated. Springback is reduced with the increase of BHF, whilst sheet metal thickness is reduced. The fillet of the punch shows little effect on the springback, whilst the fillet of die has great effect on the springback of the flange. The thickness of blank has more effect on springback than that of BHF.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2007年第2期269-272,共4页
Materials Science and Technology
基金
江苏省自然科学基金资助项目(BK20002009)
