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:
“Croft had an instinctive knowledge of land, sensed the stresses and torsions that had first erupted it, the abrasions of wind and water. The platoon had long ceased to question any direction he took; they knew he would be right as infallibly as sun after darkness or fatigue after a long march.”
—Norman Mailer (b. 1923)
“All conservatives are such from personal defects. They have been effeminated by position or nature, born halt and blind, through luxury of their parents, and can only, like invalids, act on the defensive. But strong natures, backwoodsmen, New Hampshire giants, Napoleons, Burkes, Broughams, Websters, Kossuths, are inevitable patriots, until their life ebbs, and their defects and gout, palsy and money, warp them.”
—Ralph Waldo Emerson (1803–1882)