(True/False) Magnitude of stress range is a factor leading to the development of fatigue cracks.

(True/False) Magnitude of stress range is a factor leading to the development of fatigue cracks.

• A. False
• B. Not sure
• C. True
• D. Both

Answer: (C)

Fatigue failure occurs from repeated loading, and the stress range in each cycle directly controls crack initiation and growth. A larger stress range means a larger stress intensity range (ΔK), which accelerates crack propagation per cycle and reduces the number of cycles needed to reach a critical crack size. In fatigue design and life prediction, higher stress amplitudes consistently lead to shorter service life, while smaller ranges can allow many more cycles before failure. So the magnitude of the stress range is indeed a factor in the development of fatigue cracks.

Fatigue failure occurs from repeated loading, and the stress range in each cycle directly controls crack initiation and growth. A larger stress range means a larger stress intensity range (ΔK), which accelerates crack propagation per cycle and reduces the number of cycles needed to reach a critical crack size. In fatigue design and life prediction, higher stress amplitudes consistently lead to shorter service life, while smaller ranges can allow many more cycles before failure. So the magnitude of the stress range is indeed a factor in the development of fatigue cracks.