Stress State with the Least Resistance to Plastic Deformation

It is shown that the minimum value of the ratio of relative yield stresses found according to the energy yield criterion in two variants corresponds to the state with the least resistance to plastic deformation. A distinction in the position of the curves corresponding to the relative yield stresses in these variants allows one to estimate the appearance of tensor nonlinearity in the material. The algorithm in use assumes the nonlinearity of characteristics as functions of stress intensity and of the aspect angle of the stress state.