ASTM defines fatigue life, Nf, as the number of stress cycles of a specified character that a specimen sustains before failure of a specified nature occurs.
One method to predict fatigue life of materials is the Uniform Material Law (UML). UML was developed for fatigue life prediction of aluminum and titanium alloys by the end of 20th century and extended to high-strength steels and cast iron. For some materials, there is a theoretical value for stress amplitude below which the material will not fail for any number of cycles, called a fatigue limit, endurance limit, or fatigue strength.
Read more about this topic: Fatigue (material)
Famous quotes containing the words fatigue and/or life:
“He is asleep. He knows no longer the fatigue of the work of deciding, the work to finish. He sleeps, he has no longer to strain, to force himself, to require of himself that which he cannot do. He no longer bears the cross of that interior life which proscribes rest, distraction, weaknesshe sleeps and thinks no longer, he has no more duties or chores, no, no, and I, old and tired, oh! I envy that he sleeps and will soon die.”
—Albert Camus (1913–1960)
“We quaff the cup of life with eager haste without draining it, instead of which it only overflows the brim—objects press around us, filling the mind with their magnitude and with the throng of desires that wait upon them, so that we have no room for the thoughts of death.”
—William Hazlitt (1778–1830)