Application of the equivalent material concept to the study of the ductile failure due to U-notches

Highlights: • Non-dimensional U-notch failure data shows a weak dependence with material. • Non-dimensional U-notch predictions presents a weak dependence with criterion. • EMC extends linear elastic results to ductile materials. • Limits of applicability are defined in terms of L_r. • EMC combined with phenomenological criteria is applicable under SSY. -- Abstract: This paper studies the applicability of the Equivalent Material Concept to the fracture of elastoplastic materials due to the presence of U-notches. This approach consists of simplifying the study of an elastoplastic material by assuming linear elastic behaviour. The maximum stress of this fictitious material is such that the deformation energy in a tensile test would be the same as for the real material. This idea combined with a failure criterion allows to establish a procedure to predict the failure of U-notched elements. The methodology has been successfully applied to five elastoplastic materials. In all of them the ratio between the plasticity level at failure and the plastic collapse load has been determined. The proposed methodology has been carefully verified and application limits have been proposed when failure occurs within the small-scale yielding regime.