6. As an engineer-in-training on spring internship, you are tasked to evaluate the safety of a pressurized tank (gauge pressure p = 10 MPa) subjected to loading (P = 25 kN) as shown. The tank is a round hollow pipe with an outer diameter of 100 mm and an inner diameter of 80 mm. Determine the principal normal stresses (Omax, Omin) and maximum shear stress (Tmax) and draw the principal stresses on a rotated 2D element showing the principal angle (0) at the location L shown on the diagram. Centroid of a circle is 4r/3. 3P P y 150 mm K L A 600 mm P 150 mm x