Question

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 15 kpsi, an alternating torsional stress of 10 kpsi, and an alternating bending stress of 12 kpsi. Find the factor of safety guarding against a static failure, and the factor of safety guarding against a fatigue failure, and find the expected life of the part. For the fatigue analysis use:

Answer 1

Factor of safety against static failure = 2.097

Factor of safety against fatique failure = 1.6

Step-by-step explanation:

Bending stress = 12 kpsi

Se = 40 kpsi,

Sy = 60 kpsi,

Sut = 80 kpsi

See the attached file for explanation