Solidworks finite element analyis reports example

(e) Estimate the average pressure loading on the pressure vessel and use the standard equations for thin-walled pressure vessels to make an estimate by hand calculation of the pressure vessel wall thickness required to give a Factor of Safety of not less than 2 using whichever of the two failure criteria gives the safer result.

Conclusion

– The weight is calculated with accuracy of -0. 22(%) for the empty vessel.
– The weight is calculated with accuracy of -0. 05(%) for the filled vessel.
– The calculated stress is verified by its comparison with hand calculated membrane stress.
– Von Mises and Tresca criteria are applied to upper and lower spherical part of the pressure vessel, with FOS larger than 2.
– Von Mises and Tresca criteria are applied to the cylindrical part of the pressure vessel, using an average Mises stress, with FOS smaller than 2.
– Von Mises and Tresca criteria are applied to lower spherical part of the pressure vessel, with FOS larger than 2.
– After the verification of stress level at the cylindrical part of the pressure vessel, with Von Mises criterion, the required thickness is calculated as 0. 042(m).
– If this pressure vessel were made with a spherical shape, FOS might have been larger than 2 as a whole.
– The wall of a pressurized spherical vessel is subjected to uniform tensile stresses in all directions.
– When a cylindrical pressure vessel is to designed, care must be taken especially failure strength of a cylindrical part.
– The longitudinal welding might better be replaced by a helical welding.

References

[1] unit 3 riveted joints-IGNOU,
[online] Available at:
[Accessed 21 Dec 2013 ].
[2] Timoshenko and Woinowsky-Krieger, 1959: Theory of Plates and Shells,
[online] Available at:
[Accessed 21 Dec 2013 ].
[3] Introduction to ASME Codes and Standards,
[online] Available at:

[Accessed 21 Dec 2013 ].
[4] Spherical Pressure Vessels,
[online] Available at:
[Accessed 21 Dec 2013 ].
[5] Brittle and Ductile Behavior,
[online] Available at:
[Accessed 21 Dec 2013 ].
[6] von Mises yield criterion,
[online] Available at:
[Accessed 21 Dec 2013 ].
[7] Maximum Shear Stress Criterion,
[online] Available at:
[Accessed 21 Dec 2013 ].