Usefulness of non-linear crack mechanics under plane strain conditions

Recently, non-linear crack mechanics was proposed by one of the authors and its usefulness under plane stress conditions was confirmed in the case of plate specimens with a center crack. Non-linear crack mechanics assures that if the y-directional plastic strain epsilon(y0)(p) at a crack tip obtained by FEM are equal to each other in a specimen (1) and a real object (2), the crack opening displacements and the elastic-plastic stress fields in both are equal to each other respectively, and therefore the same phenomena occur in the specimen and the real object, where the y-direction is the direction normal to the crack. Originally, linear fracture mechanics should be called linear crack mechanics. The non-linear crack mechanics is a direct extension of linear crack mechanics[1].