Issue 43

B. Saadouki et alii, Frattura ed Integrità Strutturale, 43 (2018) 133-145; DOI: 10.3221/IGF-ESIS.43.10

N f

number of cycles to failure ultimate tensile strength

UTS

R

load ration

W f

total energy to failure

YS 0. 2% YS’ 0.2%

conventional yield strength at 0.2 of strain

conventional yield strength at 0.2 of strain in cyclic tensile stress corresponding to 1% of tensile plastic deformation

σ 1 σ a

alternative stress stress amplitude true stress at failure

σ amp

σ f

σ’ f σ m

fatigue resistance coefficient

mean stress

σ max σ min

maximum stress minimum stress true strain at failure

ε f

fatigue ductility coefficient

ε ’ f

∆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

145