What is the consequence of the fatigue life being exceeded in a material?

When the fatigue life of a material is exceeded, it means that the material has undergone repeated loading and unloading cycles that have exceeded its capacity to endure such stresses without sustaining damage. As a result, the material develops microscopic defects that can grow over time, leading to cracks.

Eventually, if these cracks propagate sufficiently, they can lead to complete material failure, which is characterized by a sudden and unexpected break or fracture of the material under loading conditions. This failure can occur without any pre-warning, making it a critical concern in engineering applications, particularly in airframe structures where safety and integrity are paramount.

In contrast, improved material strength, temporary deformation, and increased flexibility do not directly result from exceeding fatigue life, as this condition primarily leads to damage and potential catastrophic failure. Understanding the nuances of fatigue life is crucial for designing components that can withstand operational demands without compromising safety.