A note on the pure torsion of a circular cylinder for a compressible nonlinearly elastic material with nonconvex strain-energy
The large deformation torsion problem for an elastic circular cylinder subject to prescribed twisting moments at its ends is examined for a particular homogeneous isotropic compressible material, namely the Blatz- Ko material. For this material, the displacement equations of equilibrium in three-dimensional elastostatics can lose ellipticity at sufficiently large deformations. For the torsion problem, it is shown that this occurs when the prescribed torque reaches a critical value.
scientific article; zbMATH DE number 753712