The progress of “c-axis tension” twinning in magnesium was represented in an analytical framework and this was used as a basis for predicting the flow stress. The difference in the stress–strain curves between tension and compression could thus be modelled with a change to a parameter that reflects the fraction of grains that undergo twinning.

An Analytical Constitutive Law for Twinning Dominated Flow in Magnesium. M.R.Barnett, C.H.J.Davies, X.Ma: Scripta Materialia, 2005, 52[7], 627-32