For the design of a thin-walled cylindrical pressure vessel, it was suggested to use a particular grade of steel with fracture toughness Kc = 35 MPa m/2 and yield strength oy = 960 MPa. The pressure vessel should have a total volume V = 600 m and is to be operated at an internal pressure of p = 16 MPa. For a thin-walled pressure vessel, the hoop stress on and the total volume V can be expressed as oh pD 2t and V LDT 4 a) If the wall thickness of the vessel is constrained to t = 0.06 m, determine the dimensions of the vessel (i.e. diameter D, length L) so that a maximum hoop stress of omax = y/2 is induced in the walls. (2 pts) b) During a maintenance check, a semicircular internal crack of depth a = 5 mm was detected (see figure). Determine the fracture stress of the pressure vessel assuming that the geometric factor is F=1.12x2/. (2 pts) c) Is it possible to meet a leak-before-break condition at a hoop stress of max = Oy/2? (2 pts) ta t