Fatigue testing is a method used to evaluate how materials or structures perform under repeated loading and unloading cycles. This type of testing helps identify the point at which a material may fail due to stress over time, which is crucial for ensuring safety and reliability in various applications, such as in aerospace, automotive, and construction industries. During fatigue testing, samples are subjected to controlled stress levels, simulating real-world conditions. The results provide valuable data on the material's endurance limit, allowing engineers to design components that can withstand long-term use without breaking. This process is essential for preventing catastrophic failures in critical systems.