Influence of Pipe Diffusion of Defects on the Amplitude Dependence of Hysteresis Internal Friction

Formulae are obtained which describe the damping decrement of hysteresis dislocation internal friction with due account of pipe diffusion of mobile pinning points. The amplitude dependence of a damping decrement is described by a non-monotoneous function which has maximum at some value of the applied stress amplitude. The asymptotic formulae are obtained for the damping decrement at low and high amplitudes. The pipe diffusion of pinning points results in the displacement of both the beginning of an amplitude dependence and the point of maximum into the region of low amplitudes. The question is dicsussed about the influence of a number of mobile pinning points and the energy of dislocation interaction with point defect on the amplitude dependence of internal friction. [Russian Text Ignored]