Ashaft is loaded in bending and torsion such that the bending moment at a critical cross section varies between 125 n. m and –15 n. m, and torsional moment varies between 80 n. m and –10 n. m. the shaft is made of steel of ultimate strength 700 mpa, yield strength of 400 mpa and a fully corrected endurance limit of 210 mpa can be assumed. the cross section is part of a stress concentration feature where kt = 2.2 and kts = 1.8. find the minimum acceptable diameter using de-goodman criterion for a safety factor of 2.0. also calculate the first cycle yielding safety factor.