Calculate the cyclic stress properties (not the principal ones) for each of the following cases: M 0 T D= 30 mm, d = 15 mm, r=0.75 mm M =50 N.m For normal stress: Stress amplitude (a) = ? Mean stress (om) = ? Stress ratio (R.) = ? D = 12 mm, d = 10 mm, r=0.75 mm T= 30 N.m, F = 10 KN For normal and shear stress: Stress amplitude (oa and ta) = ? Mean stress (Om and Tm) = ? Stress ratio (Ro and Rc) = ?