It would be very handy if uniaxial compression was the same as biaxial tension. But is it? This article has the answer.
Theory of how the constitutive elements influence the predicted yield stress dependence on strain rate
Review of how different material models can be used to predict the non-linear response of PC. Also covers how the yield stress depends on the strain rate.
Quick discussion about the math behind stress relaxation and creep in polymers.