Three-dimensional effects in finite thickness plates weakened by rounded notches and holes under in-plane shear

It is well known that in cracked plates under in-plane shear loading, an induced out-of-plane mode, due to the Poisson's effect, is automatically generated. Some recent studies have shown the importance of this coupled mode (called mode O) in plates weakened by sharp V-notches characterized by different notch opening angles. Particular attention has been paid to the scale effect focusing also on the implications of the coupled mode to different material scale levels. Also when the notch root radius is different from zero, the out-of-plane mode continues to exist, and its intensity with respect to the generating mode depends on the notch radius and the plate thickness. Aim of this paper is to discuss the main features of the out-of-plane mode dealing with three-dimensional plates weakened by blunt notches. In particular, some results from blunt V-notches, circular and elliptic holes are discussed in detail and presented here. The main key-point highlighted in the present contribution is that always three-dimensional effects exist in finite thickness plates, because mode I, II and III cannot exist in isolation. The importance of induced modes varies from case to case and depends on the geometry of the component and on the externally applied load. These effects cannot be neglected a priori even if, in some cases, they may be negligible.