Elasticity Matrix for Composite Materials

Hello,

I'm trying to find the effective material properties of a composite representative volume element. I've been trying to use periodicity or separate load cases and expect anisotropy in the resulting properties due to the geometry of the composite's constituents. However, when I solve the model for the load cases to populated the elasticity matrix, the resulting values are all the same for every component and every case. How is the elasticity matrix derived value calculated?

Thanks,

Denise