Fatigue testing measures how many cycles to failure under repeated loading. What does this test quantify?

Fatigue testing measures how many cycles to failure under repeated loading. What does this test quantify?

• A. The number of cycles to failure under repeated loading
• B. The maximum load achieved in a single test
• C. The material's hardness at failure
• D. The ultimate tensile strength at room temperature

Answer: (A)

Fatigue testing measures the material’s fatigue life under cyclic loading. It quantifies how many loading cycles the material can endure before it fails, capturing the time-to-failure in terms of cycles rather than a single peak load. This reflects how cracks initiate and propagate under repeated stress, and the result is often used to build S-N curves that relate stress amplitude to cycles to failure for predicting service life. It is not about the maximum load in one test, hardness at failure, or the monotonic ultimate tensile strength measured in a single, non-repeated test.

Fatigue testing measures the material’s fatigue life under cyclic loading. It quantifies how many loading cycles the material can endure before it fails, capturing the time-to-failure in terms of cycles rather than a single peak load. This reflects how cracks initiate and propagate under repeated stress, and the result is often used to build S-N curves that relate stress amplitude to cycles to failure for predicting service life. It is not about the maximum load in one test, hardness at failure, or the monotonic ultimate tensile strength measured in a single, non-repeated test.