A bar of steel has the minimum properties Se = 40 kpsi, Sy = 60 kpsi, and Sut = 80 kpsi. The bar is subjected to a steady torsional stress of 6 kpsi and an alternating bending stress of 23 kpsi. Find the factor of safety guarding against a static failure and either the factor of safety guarding against a fatigue failure or the expected life of the part. For the fatigue analysis, use 1.  Modified Goodman criterion 2. Gerber criterion 3. Morrow criterion Take τa = 0 kpsi and σm = 0 kpsi.   NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part.   What are the values of the alternating and mean von Mises stresses?    The alternating von Mises stress is  kpsi. The mean von Mises stress is  kpsi.

A bar of steel has the minimum properties S_e = 40 kpsi, S_y = 60 kpsi, and S_ut = 80 kpsi. The bar is subjected to a steady torsional stress of 6 kpsi and an alternating bending stress of 23 kpsi. Find the factor of safety guarding against a static failure and either the factor of safety guarding against a fatigue failure or the expected life of the part. For the fatigue analysis, use

1.  Modified Goodman criterion

2. Gerber criterion

3. Morrow criterion

Take τ_a = 0 kpsi and σ_m = 0 kpsi.

NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part.