Stress state with the least resistance to plastic deformation

It is shown that the minimum value of the relation of relative limits of fluidity found according to the power criterion of fluidity in two variants is an index of the state with the least resistance of flowage. A distinction in the position of charts for the relative limits of fluidity in these variants allows one to estimate the manifestation of tensor nonlinearity by the material. The algorithm of the methodology assumes the nonlinearity of characteristics as functions of stress intensity and of the aspect angle of the stress state.