Issue 43

B. Saadouki et alii, Frattura ed Integrità Strutturale, 43 (2018) 133-145; DOI: 10.3221/IGF-ESIS.43.10 145 N f number of cycles to failure UTS ultimate tensile strength R load ration W f total energy to failure YS 0. 2% conventional yield strength at 0.2 of strain YS’ 0.2% conventional yield strength at 0.2 of strain in cyclic tensile σ 1 stress corresponding to 1% of tensile plastic deformation σ a alternative stress σ amp stress amplitude σ f true stress at failure σ’ f fatigue resistance coefficient σ m mean stress σ max maximum stress σ min minimum stress ε f true strain at failure ε ’ f fatigue ductility coefficient ∆σ 1 Stress variation between the stress levels of the monotonic and cyclic tensile curves for 1% of plastic deformation ∆ ε el elastic strain variation ∆ ε p plastic strain variation ∆ ε t total strain variation ∆W mechanical strain energy