Numerically predicted J-integral as a measure of crack driving force for steels 1.7147 and 1.4762

Abstract

Fracture behavior of two types of steel (1.4762 and 1.7147) is compared based on their numerically obtained J-integral values. The J-integral are chosen to quantify the crack driving force using the finite element (FE) stress analysis applied to single-edge notched bend (SENB) and compact tensile (CT) type fracture specimens. The resulting J-values are plotted for growing crack length (∆a -crack length extension) at different a/W ratios (a/W -relative crack length; 0.25, 0.5, 0.75). Slightly higher resulting values of the J-integral for 1.4762 than 1.7147 can be noticed. Also, higher a/W ratios correspond to lower J-integral values of the materials and vice versa. J-integral values obtained by using the FE model of the CT specimen give somewhat conservative results when compared with those obtained by the FE model of the SENB specimen.

DIC‐based J‐integral evaluation of laser repaired cracks with micro/nanomaterial addition

“…25 It is an important parameter in elastic-plastic fracture mechanics, for instance, a measure of the crack driving force. 26,27 Supposing a homogeneous plate with a penetrating crack on it, and the crack surface is a free, but the external load causes a two-dimensional stress and strain fields around the crack, then the J-integral is defined as…”

“…J ‐integral is a fracture parameter independently proposed by Cherepanov and Rice . It is an important parameter in elastic‐plastic fracture mechanics, for instance, a measure of the crack driving force . Supposing a homogeneous plate with a penetrating crack on it, and the crack surface is a free, but the external load causes a two‐dimensional stress and strain fields around the crack, then the J ‐integral is defined as where Γ is an arbitrary contour encompassing the crack tip; w is the strain‐energy density and defined as where σ kl and ε kl are the stress and strain tensor, respectively, at any point on the path Γ, u is the displacement vector on the path Γ, and d y is the increment of y .…”