Energy-based evaluation of the stress concentration factor with highly non-regular coarse meshes: theoretical formulation and practical validation

The main aim of this work is to propose a simple and highly accurate approach to evaluate the stress concentration factor of notched solids under Mode 1 loading by using non-regular coarse meshes and the elemental averaged strain energy. As a first step of the analysis, the analytical expression for the Strain Energy averaged over a four-sided and three-sided finite element located at the notch tip is derived, taking advantage of Filippi-Lazzarin-Tovo equations for rounded notched plates under pure Mode 1 loading. Subsequently, the accuracy of the proposed approach is widely validated taking advantage of a large number of examples related to U-shaped notches and rounded V-shaped notches with different notch root radii.