fatigue
Fatigue can be described as the gradual degradation of metal due to continued cyclical strain and eventually leads to the development of cracks and damage over time, irrespective of the load application lower than the ultimate strength of the material.

Key Features:

  • Cyclic Loading: It occurs due to the application of fluctuating and alternating stresses usually repetitively.
  • Initiation and propagation of cracks: These small cracks that form at the point of stresses grow with time until failure occurs.
  • Fatigue Life: This refers to the number of cycles that a material may withstand before it fails and is influenced by the level of stresses and environmental factors.

Critical Fatigue is concerned with industries like aerospace, automotive, and civil engineering. In these industries, components suffer normal stresses continuously for example aircraft wings, car suspension systems, bridges, etc. The design of these components takes into consideration the material's high fatigue strength and safety margins to avoid fatigue failure. Advances in material science along with improved methods of fatigue testing will help make safeties by durability and longevity of components in use.