A circular tube must support an axial load of 60 kN in tension and a torque of 1.0 kNm. It has an inside diameter of 46.0 mm and is made of 7075-T6 aluminum, for which the uniaxial yield stress is 450 MPa.
(a) What is the safety factor against yielding if the wall thickness is 2.5 mm?
(b) What adjusted value of wall thickness with the same inside diameter is required to obtain a safety factor against yielding of 2.0?