“…The results of studies on viscoplastic properties of titanium alloys and steels under cyclic loading show [1,2] that their life estimation should be performed with the account of directed plastic deformation kinetics. One of the optimum versions of life calculations can be the calculation with the deformation-kinetic criterion developed at our Institute [3]: where ¢ C i is the parameter of deformation properties of the material and a stress state, determined according to [4] from the condition of plastic deformation stability loss under stepwise cyclic loading, s i max is the maximum stress intensity in the cycle, and s itr is the stress of fatigue-to-quasistatic fracture transition, determined from the condition of plastic deformation stability.…”