Issue 43

F.Z. Seriari et alii, Frattura ed Integrità Strutturale, 43 (2018) 43-56; DOI: 10.3221/IGF-ESIS.43.03 56 N OMENCLATURE a Crack length a ol Crack length at applied overload a 0 Initial crack length BC Bending correction C, n Material constants of fatigue crack growth da/dN Fatigue crack growth rate Ep Cracked structure’s Young modulus E L Young modulus of composite patch in longitudinal direction E R Equivalent Young modulus of the patch perpendicular to the crack E T Young modulus of composite patch in transversal direction f Crack closure factor f(a/W) Finite geometrical correction function Gxy Shear’s modulus of adhesive film G LT Shear’s modulus of composite patch K I Stress intensity factor for cracked structures K IP Stress intensity factor for cracked structures with patch K IC Critical stress intensity factor for plane strain K C Critical stress intensity factor for plane stress  K I Amplitude of stress intensity factor  K th threshold of stress intensity factor K crit Critical stress intensity factor K Imax Maximal stress intensity factor K maxeff , K mineff effective stress intensity factor Kr Residual stress intensity factor Lr Length of composite patch R Stress ratio SORL Overload zone factor ORL Overload ratio CAL Constant amplitude loading VAL Variable amplitude loading R eff Effective stress ratio R y(ol) Yield zone created by overload N D /N CAL Retard ratio Wp Width of plate W r Width of composite patch I Total moment of inertia tr thickness of patch tp Cracked structure’s thickness, y max Distance of the outer sheet edge from neutral axis p’ , q’ Constant empirically derived from experimental fatigue crack growth rate p, q Length of applied spectrum at constant and variable amplitude  aMax Maximum applied stress  Remote uniform tensile stress  e Equivalent stress  t Transferred stress  0.2 Limit of elasticity at 0.2%  Poisson’s coefficient UTS Ultimate tensile stress