希尔新屈服准则[1]的另一简化形式

A NEW ABBREVIATED FORM OF THE NEW YIELD CRITERIAN BY R.HILL

皮尔斯(Pearce)(2)在1966年发现当平均厚向异性指数R小于1时,板材双向等拉应力—应变曲线在单向拉伸曲线之上,而理论预测它是低于单向拉伸应力—应变曲线。即所谓的“反常特性”。希尔提出了一种非二次屈服函数[1]能包容这种情况,但是此函数是假定面内同性。 本文从希尔新屈服准则出发,得出另一种平面应力下能反映面内异性的屈服函数,此函数能包容“反常特性”。

Roget Pearce found that yield strength of metal sheets with R<1 in biaxial tension were greater than those in uniaxial tension. This is an anomalous behaviour. One nonquadratic yield function proposed by R. Hill can be adopted to explain this anomaly, but this yield function assumes planar isotropy.In this paper, a new abbreviated form of the new yield criterion of the Hill's type is proposed for planar stress conditions. This suggested criterion does not assume plane isotropy and can explain the anomaly.