Three-dimensional elastic stress fields near crack front at V-notches

The objective of this paper is to study the elastic fields ahead of crack front in the double edge notch plates subjected to uniaxial tensile. Based on three-dimensional finite element analyses, the effect of different notch angles, plate thickness and crack length on stress intensity factors (SIF) and out-of-plane stress constraint factors (T_z) are revealed and the scale of 3D constraint area is also analyzed. When the notch angle β≤60°, the distribution of SIF and T_z follow the same rule. The SIF are different through the thickness. The SIF in mid-plane is higher than that in free surface or in 2D solution, but as the increasing of plate thickness it decreases. The location of maximum SIF is transferred from mid-plane to there near the free surface, when B/d≥15. If the crack is longer than the notch size (c/ρ>1), the notch can be considered as part of a flat crack of length (d + c). There has the largest value of 3D constraint effect zone in mid-plane, which is about 45% of thickness. It decreases with the increasing distance from mid-plane and up to zero in free plane.