Abstract: This paper provides a comprehensive description, and the subsequent validation, of a structural integrity
assessment methodology of structural materials containing notch-type defects. The approach is based on the
combination of Failure Assessment Diagrams (FAD) and the Theory of Critical Distances (TCD). The former
provides the general assessment tool, which is exactly the same one as that used for crack-like defects, whereas the latter provides the notch effect correction required for the analysis of this type of defects. Finally, the proposed methodology is validated on a number of metallic and non-metallic structural materials, with 1,106
experimental results on different types of testing specimens, covering four structural steels, aluminium alloys
7075-T651 and 6060-T66, PVC, PMMA, PA6, fibre-reinforced PA6, 3D printed (Fused Filament Fabrication) ABS, PLA and graphene reinforced PLA, granite and limestone. The results show how the FAD-TCD methodology provides safe reasonably conservative assessments on the mentioned structural materials in the presence of notch-type defects.