The equation of a contour and the form factor of a hysteresis loop

A procedure for the determination of the parameters of actual diagrams of cyclic deformation is developed on the basis of experimental and theoretical investigations of cyclic stress-strain diagrams for steels. This diagram characterizes the dependence of strains on stresses in a loading cycle in the region of the transition from low-cycle fatigue to multicycle and proper multicycle fatigues. The correspondence between the amplitudes of plastic and residual deformations is established and the formula for the determination of the form factor of a hysteresis loop is proposed. Numerical data are compared with experimental results for 45 and 15313 steels and with data obtained by other authors. Translated from Problemy Prochnosti, No. 3, pp. 30–38, May–June, 1997.