A new simplified method to model large ductile tering crack growth applicable to specimens and structures

摘要

Several simplified methods allow to evaluate the harmfulness of a defect located in a structure. However, they use parameters non intrinsic to the material as the J- DELTA a curve. A new method using two parameters is proposed to solve the problem of transferability of parameters between components of different sizes. The first is a characteristic value of the J integral, J_i, determined from the size of the stretched zone. The second parameter, noted G_fr, represents the energy dissipated in the fracture process during the propagation. This term, associated to a finite increment of crack extension lambda , allows to define the critical parameter G_c which govers the crack propagation.