Question

A cross section of a pressure vessel use to store high pressure gas at 15MPa pressure is shown in Figure Q4. A FEA analysis for this pressure vessel was performed using a quarter solid model and a 2D Axisymmetric model. Contour plots of the hoop stress and longitudinal stress of the top and the bottom of the pressure vessel is attached to this exam paper (Figures Q4-1 to Q4-4). Modulus of Elasticity of Steel = 200GPa, Poisson’s ratio 0.3, Strength of the boiler steel can be assumed as 450 MPa, outside diameter of vessel is 500 mm, length of cylindrical part of the vessel is 2m and the thickness of the plate is 20 mm. (a) Calculate hoop and longitudinal stresses at the walls of the pressure vessel due to internal pressure 15 MPa

Outer Radius 250 mm Table 1 FEA details 50 m Dia Hale- Model Type: Three Dimensional Model Type: 2D Axisymmetric 4366 Points: Points 5688 Wall thickness 20 mm Stoal plate Edges 28206 Edges: 8585 oikcoa's cat 0 Faces: 39729 Faces: 4220 Solids 2D Solids 17210 4220 Elements Elements: 17210 4220 Total Elapsed Time (seconds): 140.25 Total Elapsed Time (seconds): 15.36 15 Mi loside Precsure (seconds): 15140 (seconds): 14.38 Total CPU Time Total CPU Time Maximum Memory Usage (kilobytes): Maximum Memory Usage (kilobytes): 1115769 984727 500 mm outside Diameter Hiqure 04 Pressure vessel

Answer 1

Given, diamelev Do outside 500 mm t thicknes 20 mm 15MPO PIntevnal premuve know ta, we D; +2t 500 - 40 (in Eide diametey. L460 mm D Hoop shew longitudinal stremes longstudinal sheM is 3iven Di D 36.25 MPa 4X20 Hoop strers is given by OH 2t 15X460 L 2X20 lOH 172.5MPa OH XRxt)=P x D