Abar 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 and an alternating bending stress of 25 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: a) modified goodman criterion. b) gerber criterion. c) asme-elliptic criterion.