In a structure subjected to fatigue loading, the minimum and maximum stresses developed in a cycle are $$200$$$$MPa$$ and $$400MPa$$ respectively. The value of stress amplitude (in $$MPa$$) is ____________.

In terms of theoretical stress concentration factor $$\left( {{k_t}} \right)$$ and fatigue stress concentration factor $$\left( {{k_f}} \right),$$ the notch sensitivity $$'q'$$ is expressed as

The $$S$$-$$N$$ curve for steel becomes asymptotic nearly at

A static load is mounted at the center of a shaft rotating at uniform angular velocity. This shaft will be designed for