All materials will fail when subjected to cyclic stress, even if the stress is at a level that would not cause failure under static loading. This is called fatigue.
Countermeasures
After a certain period of use, it is necessary to perform the following inspections and evaluations to prevent fracture:
- Subcategory: Fatigue
- Damage mode: Cracks
- Inspection: Visual inspection, liquid penetrant testing, ultrasonic testing, magnetic particle testing (for steels).
- Evaluation: Detection of cracks, measurement of their presence, and depth, length in areas where crack formation is possible.
- Actions: Establish criteria for crack removal, repair, component replacement, and elimination of damage causes (stress and shape etc.).