Question 3: (22 points) A crane is using straps and a spreader beam to pick up a pressure vessel. The propane tank has an inner diameter of 600 mm inches and a wall thickness of 15 mm. The internal forces on the propane tank due to is self-weight and the way it is lifted are the following: Normal force = 1200 kN (compressive) Bending moment = 2500 kN-m (compressive at the top of tank, bending about axis shown in cross section), • Torque = 400 kN-m (clockwise in cross section In addition, the tank was under a 6 MPa internal pressure during the lift. Determine the total normal and shear stresses (x, y, and Txy) on an element on the outside of the tank as shown: уф Element Element Ө Cross Section