Several variables come into play in the mechanism and rate of fatigue fracture:

• Magnitude of Stress: The amplitude of cyclic stress plays a pivotal role. Higher stress magnitude can expedite fatigue fracture.
• Number of Cycles: Even low-stress levels can induce failure if the number of applied cycles is sufficiently high.
• Stress Concentrations: Notches, sharp corners, or any geometric irregularities in a component can act as stress risers, intensifying the local stress and becoming initiation points for cracks.
• Operating Environment: Corrosive environments can accentuate fatigue damage, leading to a phenomenon known as corrosion fatigue.

Controlling and mitigating fatigue fracture is pivotal for the integrity of cyclically loaded structures. A few key mitigation measures include:

• Material Selection: Choose materials with high fatigue resistance. The material’s microstructure, purity, and heat treatment can influence its fatigue performance.
• Smooth Transitions: Eliminate sharp notches, corners, and abrupt changes in cross-section in design, which can act as stress concentrators.
• Protective Coatings: Apply functional coatings to protect the metal from environmental factors, reducing the risk of corrosion fatigue.
• Residual Stresses: Introduce beneficial residual compressive stresses on the material surface using techniques like shot peening or laser peening. This can hinder the initiation and propagation of fatigue cracks.
• Regular Inspection: Deploy non-destructive testing (NDT) techniques like ultrasonic testing, dye penetrant testing, or magnetic particle testing to periodically inspect components for the initiation and propagation of cracks.
• Design for Redundancy: Desing components in such a way that if one part fails, the load can be redistributed to prevent a total catastrophic failure.