MODELLING THE BRITTLE-DUCTILE TRANSITION
脆—韧转变的模型化

Many crystalline solids fail by cleavage at low temperatures. and by plastic processes at high temperatures. In the transition region cleavage failure occurs at stresses increasing with increasing temperature. reflecting a decrease in yield stress. and a consequent increase of plasticity around the crack tip. Crack tip plasticity blunts the crack and shields it through compressive stresses in the plastic zone. This paper gives a brief review of a model of the brittle-ductile transition in which the shielding is calculated from a plastic zone formed by the generation (from a source). motion and interaction of dislocations moving on a slip plane containing the crack tip. and obeying a velocity/stress/temperature law. The application of the model to experiments is discussed.