Dislocation-related inelastic phenomena at different damping levels

A numerical investigation is made into the dynamics of steady-state oscillations of an isolated dislocation loop over a wide interval of forced oscillation frequencies and at different levels of damping. The dependence of the dislocation-related strain and power dissipation on the external stress is found for different levels of damping. The amplitude dependences of such integral characteristics of the dynamics of dislocation motion as the internal friction, the elastic-modulus defect, and the ratio of the two are investigated. A critical value of the damping level of the dislocation loop is found at which the dislocation hysteresis begins to lose its static character and starts to take on dynamic traits. The features of the formation of dislocation hysteresis under conditions of its transformation from a static to a dynamic type are established. (C) 2000 American Institute of Physics. [S1063-777X(00)00603-4].