Assessment of notched structural components using Failure Assessment Diagrams and the Theory of Critical Distances

Abstract

This paper illustrates the need to develop specific methodologies for the assessment of notched structural components. These are usually analysed under the assumption that notches behave as cracks, providing results that may be overconservative. The proposal consists, on the one hand, in the application of the Theory of Critical Distances for the estimation of the apparent fracture toughness, and for the conversion of the notched situation into an equivalent cracked situation in which the material develops a higher fracture resistance (the apparent fracture toughness). On the other hand, once the apparent fracture toughness has been defined, the assessment is performed using the Failure Assessment Diagram methodology, and assuming that the notch effect on the plastic collapse load is negligible. The methodology has been applied to notched fracture specimens made of PMMA and Al7075-T651, providing satisfactory results and a noticeable reduction in the overconservatism derived from analyses in which the notch effect is not considered.