What is fatigue in materials?

Fatigue in materials refers specifically to the weakening of a material that occurs due to the application of repeated loads over time. This process leads to the gradual accumulation of damage, which can eventually result in failure even if the loads are below the material's ultimate strength. Unlike other types of stress, which may be applied only once or in a steady manner, fatigue involves the fluctuation of stress levels, causing microscopic cracks to develop and grow within the material.

Understanding fatigue is crucial in engineering and materials science because it allows for better design and prevention strategies to ensure that structures and components can withstand their intended use over extended periods. The phenomenon is particularly relevant in applications where materials experience cyclical loads, such as in bridges, aircraft, and machinery. Recognizing the implications of fatigue helps engineers select appropriate materials and design components to minimize the risk of unexpected failures.