Pipe elbow stress modelling 1

[yoojeen]

I have ultrasonic data for a thick walled elbow that show the pipe wall thinning (due to errosion / corrosion) however the wall thickness is non-symetrical at various cross sections and is more pronounced in the turn of the elbow. From this data I can develop a 3-D model. I need to identify the maximum principal stresses in the elbow. I have access to ansys and abaqus but there is no basic model for this application in the library of either program. Does anyone know where I can obtain a base model for this application in ansys or abaqus or does anyone recommend another program for this application? Do I superimpose the thermal stress results with the hoop stress results? I have been required to use an FEA program to provide a look at the stress profile but should I pull out my Peng and Peng book and just look at the stresses where the wall thickness is a min?Thank you in advance for any help.

 

[MrMyers]

Take a look at API-579/ASME FFS-1. What you are trying to do is considered a "Level 3" analysis.

However, there is such a thing as a "Level 2" analysis which does not require the use of FEA, and is ananalytical approach you can do on a spreadsheet.

I'd start with a Level 2 analysis, and only perform Level 3 if it is necessary.

All the best.

 

[LSThill]

yoojeen (Mechanical)

Technical Note:

Please: have you review API 579 & A.S.M.E FFS-2 (2009) Fitness for Service - Example Problem Manual

http://files.asme.org/catalog/codes/printbook/21639.pdf

Using International Standards to Support the Life-Cycle Management of Pressurized Fixed Equipment

http://www.tappi.org/content/events/11opex/papers/osage.pdf

steve

 

[yoojeen]

Thanks Steve and Mr. Meyers for the lead. I really did not know where to start.

Gene

 

[yoojeen]

Mr. Steve or Mr. Meyers in the FFS-2 manual they reference a "MAT" - which is a design requirement temperature but it is never defined. Do you know what "MAT" refers to and how it is defined?

thanks
Gene

 

[TGS4]

Check out paragraph 3.1.4.

 

[LSThill]

TGS4 (Mechanical)

Thank you

Steve

 

[LSThill]

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