Topic: Machine Design
Fatigue strength for non-ferrous materials is usually defined at _________ stress cycles.
- A. $10^{4}$
- B. $10^{7}$
- C. $10^{9}$
- D. $10^{12}$
Answer: B. $10^{7}$
Explanation: For non-ferrous materials, there is no particular limiting stress (i.e. endurance limit). As stress reduces, the number of cycles to failure keeps increasing. Hence, the strength corresponding to $10^{7}$ or $5 \times 10^{8}$ cycles is considered as characteristic of the material and is known as fatigue strength.