A non-ellipticity result, or the impossible taming of the logarithmic strain measure

Robert J. Martin, Ionel-Dumitrel Ghiba, Patrizio Neff

The logarithmic strain measures $\Vert \log U{\Vert }^2$, where $\log U$ is the principal matrix logarithm of the stretch tensor $U=\sqrt{F^{T}F}$ corresponding to the deformation grad…