Consider a solid circular shaft subjected to bending and torsion so that the state of stress of interest involves only a normal stress and a shear stress, with all other stress components being zero.
(a) Determine the safety factor against yielding as a function of the yield strength of the ductile material and the applied stresses.
(b) Use the results of (a) to develop a design equation for the shaft giving diameter d as a function of yield strength, safety factor, bending moment M, and torque T.