Interpreting FEA results
Interpreting FEA results
(OP)
Guys, I am performing design analysis using ANSI/ALI which is mostly based on hand calculations. Obviously, my stress analysis results are going to be higher than those obtained by hand calculations. Is there a fudge factor I can use to address this discrepancy?
Thanks.
Thanks.





RE: Interpreting FEA results
I recommend you do some design validation problems to make sure you are using the software properly...some simple geometries from Roark's or your college textbooks.
RE: Interpreting FEA results
corus
RE: Interpreting FEA results
I'm wondering if you are referring to results associated with restraining bolt holes or other similar geometry which can result in singularities and values that are artificially high.
RE: Interpreting FEA results
RE: Interpreting FEA results
RE: Interpreting FEA results
Occasionally one gets stuck with old permissible stress codes when trying to use FEA. At its most ridiculous someone will compare peak unsmoothed FE stresses based on stresses at integration points interpolated to nodes, to the allowable stress in the code.
If you cant ignore the permisible stress code or change to a limit state code, then it seems you could be destined for an uneconomical solution.
RE: Interpreting FEA results
I have also dealt with independent third party inspectors that verified the stress numbers and the 100% inspection of the vessels. I would contact the inspector if this fits your case or the governing body that wrote the specification. The governing body should be able to aid you.
Good luck.
RE: Interpreting FEA results
corus
RE: Interpreting FEA results
http://www.eng-tips.com/viewthread.cfm?qid=211759
There is a black hole in the codes when FEA is used,
and that is why you often find statements like "The maximum stress is local therefore allowable".
And I agree that FEA usually gives more accurate but also higher stresses.
What we need as engineers is a solid guideline or code that defines a) what stress to use - ie which equivalent stress or which axial stress, b) what is maximum allowable, c) how big and large can peak stresses be.
So far I have not found answers to above issues.