Influence of the stress field of a tilt boundary on a Frank-Read source generating dislocations under the action of ultrasound

The influence of a nonuniform field of internal stresses and the generation of a dislocation loop by a Frank-Read source operating under the action of an alternating load is investigated by computer simulation. It is shown that the field of a tilt boundary affects every stage of development of a dislocation loop until its closure. The influence of the boundary field is determined by the ratio between the length of the source and the space scale of the field nonuniformities. It is established that not only the value of the dynamic yield point but also the form of its dependence on the ultrasonic frequency can vary in an internal stress field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 35–39, February, 1985.