1) Define effective stress, how it was derived, and how it is used.

2) Sketch a modified Goodman's diagram for tensile loading, label the axis clearly, and, for a given load case, sketch components which define the case 3 fatigue safety factor.

3) What are the three main differences in contact stresses between rolling without sliding and rolling with sliding. How does this affect surface fatigue failure?

4) Explain why it is so important to control preload in a fatigue-loaded, bolted joint. What is the joint stiffness factor and how does it affect fatigue-loaded bolted joint design?