Pile-ups of screw dislocations in two-phase systems

Pile-ups of screw dislocations in two-phase systems are analyzed using the method of continuously distributed dislocations and the polynomial method. The two-phase systems considered here can broadly be divided into two categories; first, when the second phase is circular in cross-section and second, when the interface is planar between the two phases. The behaviour of shear cracks is investigated by treating them as double pile-ups of screw dislocations. Relationships are established among various parameters connected with the pile-ups and extended towards quantitative criteria for propagation of cracks in two-phase systems. The plastic relaxation of the shear cracks is also investigated and conclusions made on the behaviour of the plastic zone. © 1974.