Fatigue is a failure mechanism caused by repeated cyclic loading that leads to cumulative damage within a material, and ultimately catastrophic failure. “Between 80% to 90% of all mechanical service failures can be attributed to Fatigue,” according to the American Society of Metals – Metals Handbook 1975 & 2008. Therefore, it is critical to test and characterize the fatigue properties of materials and components.
Fatigue failures occur when a material is loaded repeatedly, but below the stress level that would cause immediate failure, and in many cases even below the yield stress of the material. With each loading cycle, damage to the material accumulates.