Repeat Problem 8.A3, except with the specimen made from Ti-6A1-4V sheet in the solution treated and aged condition for a fatigue cycle minimum stress of 30 ksi and repeat again for a fatigue cycle minimum stress of 60 ksi.

Problem 8.A3

Consider a polished, unnotched specimen made 300M alloy forging loaded in the longitudinal direction (see page MH2-60). It is subjected to a fatigue stress cycle that ranges between minimum and maximum stress levels of 50 ksi and 150 ksi, respectively. Determine the number of cycles to failure according to the equivalent stress model. Repeat this calculation if the maximum stress remains unchanged while the minimum stress is reduced to 25 ksi.