Strain-energy failure criterion for rigid-plastic bodies

In the framework of the theory of strain-hardening rigid-plastic bodies, we suggest a strain-energy failure criterion. The strain states of a rigid-plastic body are depicted as points in the principal strain space and form a third-order hyperbolic surface for incompressible bodies. The strain processes are depicted by lines on this surface. The loading surface related to the strain surface lines is introduced, which permits calculating the energy dissipation as a parameter determining the failure.