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:
“Avarice is generally the last passion of those lives of which the first part has been squandered in pleasure, and the second devoted to ambition. He that sinks under the fatigue of getting wealth, lulls his age with the milder business of saving it.”
—Samuel Johnson (1709–1784)
“If it is asserted that civilization is a real advance in the condition of man,—and I think that it is, though only the wise improve their advantages,—it must be shown that it has produced better dwellings without making them more costly; and the cost of a thing is the amount of what I will call life which is required to be exchanged for it, immediately or in the long run.”
—Henry David Thoreau (1817–1862)