Can someone help me to explain the derivation of the coefficent ?
In the paper "A theory of the yielding and plastic flow of anisotropic metals", the Hill 48 yield criterion:
The quadratic Hill yield criterion for thin rolled plates (plane stress conditions) can be expressed as:
However, in the book of "塑性・粘弾性" link: http://www.worldcat.org/title/sosei-nendansei/oclc/047515845
the Hill's yield criterion was described as below.
Thanks.