Ogden or Hill Model for rubber foam material

[tech_sks]

Dear sir,

I have tried using Ogden multiple term model for fitting rubber foam experimental data (in compression) and I find very nice correlation. But in practice, these parts also see some amount of shear and bi-axial compression. In this situation, built Ogden model fails at some elements due to negative strain energy.
Is there another model for doing this? Or is it must to have other state's data, as in case of rubber material models (I presume).

thanks,
shashikant