Issue 43

L.C.H. Ricardo, Frattura ed Integrità Strutturale, 43 (2018) 57-78; DOI: 10.3221/IGF-ESIS.43.04 60 crack length defined by a e is referred to as the effective crack length in the literature. The conditions of equilibrium for an immobile crack tip include internal and external forces per unit length [15,16]. In such a case, the areas related to the shedding loads P s and P ys due to yielding, as indicated in Fig. 2, are equal; that is AP s =AP ys when the plastic zone size is r << a Mathematically, these loads are the equilibrium forces per unit length defined by [16]. Figure 1 : Yielding Mechanism of a Plate [6, 7]. Figure 2 : Crack Tip Plastic Zone [16].        1 0 r s ys P B dx (2.5)