Stateczność wstępnie sprężonego walca kołowego przy skręcaniu

A simple circular cylinder is subject to finite deformation by cutting out (or inserting) of a segment with an arbitrary vertex angle; the edges of the cut are welded together. Such a prestressed cylinder is then subject to finite torsion and extension. The stability of the cylinder is investigated by means of superposition of a small two-dimensional state of strain upon the finite strains. The stability conditions at small values of the vertex radius of the inclusion are presented.