Effects of geometrical parameters on the stress field of three-dimensional plates weakened by periodic notches

In this study, through-the-thickness stress field and the maximum stress location of flat plates with periodic blunt notches by using the three-dimensional finite element analysis are investigated. In particular, the effect of variation of six geometrical parameters as: the plate thickness, the ratio of notch depth to width of the plate, the pitch of periodic notches, the notch opening angle and the notch tip radius on the through the thickness stress state and location of the maximum stress are studied. More than five hundred three-dimensional geometrical configurations are analyzed. Results of this study show that, for relatively thin plates, the maximum stress of middle notch appears to be at the mid-plane and that confirms the plane stress assumption of two-dimensional finite element models. However, increasing the plate thickness leads to a shift in the location of maximum stress from the mid-plane towards the free surface of the plate. Increasing the number of notches with the purpose of decreasing stress values at the notch tip is possible, just when the pitch of the notches is relatively small. Furthermore, among the mentioned geometrical parameters, pitch variation (in particular for the case of relatively thin plates) has the most important influence on the location of the maximum tensile stress at the middle notch of periodic notched plate