FEA of Ductile Cast Iron pressure vessel

[gurmeet2003]

I work for a compressor manufacturing company. Currently we use ASME Section VIII to design compressor cylinders. By designing I mean figuring out thickness of walls and deciding reinforcement around holes. Strictly speaking code is not applicable to compressor cylinders. However we have used it successfully for a number of years. In order to validate new designs we carry out a burst test on one piece and use the code specified factor to arrive at the MAWP from the burst pressure.

Now we are trying to use FEA for design. The pressure ratigs are around 3000 psi or lower. My question is as follows:

1. Should we use Non linear FEA to predict the burst pressure and continue to use burst testing for validation.?
2. Or Can we use FEA based on service loads (pressure, bolt loads etc.)? If we use FEA only then how is FEA validated for pressure vessels? Does code or any similar publications provide guidelines for this?

I would appreciate any information on above point.

Thanks,

Gurmeet

 

[corus]

One of the benefits of FEA is to save money on tests. I wouldn't base any calculation on a single test as that particular sample may have had some kind of peculiarity in either material property or design to invalidate that test.

Normally Design by Analysis techniques are used to assess pressure vessels with FEA, given the appropriate design loads. I'd refer to the British Standard on Pressure Vessel design, or the ASME VIII codes. Both are similar.

corus