Doubt Regarding Homogenised flow curve from a two phase 3D RVE

Hi all,

I am working on getting a homogenised flow curve from the uniaxial deformation modelling of a two phase 3D RVE under periodic boundary conditions, to compare it with experimental flow curve. I have seen most of the works in literature taking the volume average of the Von-Mises equivalent Stress <S_equivalent> and Equivalent plastic strain <PE_equivalent> over the entire volume of the RVE, and comparing with the experimental. On the contrary, instead of von-mises equivalent stress <S_equivalent>, there is litterature available wherein people have computed the volume homogenised individual stress components e.g <S11>, <S22>..etc over the RVE. My doubt is , instead of taking the volume homogenised von-mises stress <S_equivalent>, is it justifiable (theoretically or even otherwise) to use the volume homogenised stress components (<S11>, <S22>..) to calculate the von mises equivalent stress from them? In other words, what is the difference between <S_equiavlent> and, equivalent stress computed using <S11>, <S22>.. and which of them is more meaningful?

Thanks!