摘要
正交弱各向异性金属板材拉深过程中,一块半径为Rb的对称圆板,放在半径为ra(ra<Rb)的冲模上,在冲头作用下,形成一个柱状杯子,由于材料的各向异性,使杯沿上出现"耳朵".假设板材为刚塑性材料并服从Hill屈服准则,推得拉深过程中,反应制耳的变量拉伸率ν=Rb/ra与Hill屈服准则系数之间的关系式和弱织构正交板材冲深过程中杯高的理论表达式(含织构系数).通过3种试样的算例得出,改变板材的织构系数,改变制耳的大小,最终达到消除制耳.
In deep drawing （ or the swift cupping test） of sheet metals, a circular blank of radius Rb is placed symmetrically under a blank-holder over a die with a circular aperture of radius ra 〈 Rb . A flat-headed punch of circular cross-section is forced down onto the blank, which is allowed to slip under the blank-holder and formed into a cylindrical cup, open at the top and closed at the base. Because of plastic anisotropy of the sheet metal, it is commonly observed that ＂ears＂ form in positions roughly symmetrical with respect to the direction of rolling in the original sheet. Under the assumption that the blank be rigid-plastic and obey Hill＇ s quadratic yield function, an explicit formula expressing the earing value of a deep-drawn cup in terms of the drawing ratio z, = Rb/ra was derived. The validity of this formula（ including texture coefficient） is examined against results of cupping tests conducted on batches of commercially pure （ L2Y2 ） aluminum blanks that had undergone various heat treatments.
出处
《应用数学和力学》
CSCD
北大核心
2013年第3期282-296,共15页
Applied Mathematics and Mechanics
基金
国家自然科学基金资助项目(10972098
11172122
51268043)
江西省主要学科学术和技术带头人培养计划项目
江西省赣鄱英才555工程项目
