Schedule 10S & 5S Piping
Schedule 10S & 5S Piping
(OP)
Is CAESAR-II an appropriate tool for use on large diameter, stainless steel, schedule 5S and 10S piping systems ?
The ASME code calculated stress intensification factors are very high, and probably not realistic.
I believe that B31.1, B31.3 and CAESAR should, in some way, address the issue of limitations in a "beam-type" stress analysis. At what point (i.e. a D/T ratio) do the local effects of bending take over and make a CAESAR-II analysis invalid ?
I feel that this issue has been addressed before and industry references exist.
I would appreciate any comments, discussions, informal company "analysis guidleines, rules-of-thumb etc.
Thanks in advance !!!............................MJC
The ASME code calculated stress intensification factors are very high, and probably not realistic.
I believe that B31.1, B31.3 and CAESAR should, in some way, address the issue of limitations in a "beam-type" stress analysis. At what point (i.e. a D/T ratio) do the local effects of bending take over and make a CAESAR-II analysis invalid ?
I feel that this issue has been addressed before and industry references exist.
I would appreciate any comments, discussions, informal company "analysis guidleines, rules-of-thumb etc.
Thanks in advance !!!............................MJC





RE: Schedule 10S & 5S Piping
I have previously used CII for the flexibility analysis only for large bore thin walled piping(D/t>100). I have calculated the SIF's from FE pipe along with the stiffness and inputted the data into CII at the fabricated intersections and bends. The wall thickness requirements have been calculated to a pressure vessel code, ie BS 5500 or ASME VIII. I hope this helps.
RE: Schedule 10S & 5S Piping
Is there anyone out there with experience on CAESAR-II modelling of thin walled systems ?
MJC
RE: Schedule 10S & 5S Piping
Re-post on COADE FORUMS www.coade.com
Leonard@thill.biz
www.thill.biz
RE: Schedule 10S & 5S Piping
Higher ratios require 3d analysis... check the notes in the SIF appendix.
Regards,
XHPIPE
RE: Schedule 10S & 5S Piping
Spend some time reading my question......
I am asking about the limitations of CAESAR-II not about the validity of the computer program nor am I asking about the validity of the notes within the appendicies to B31.3.
I am fully aware of the code's D/t< 100 limitation.
Some mechanics of materials texts state that, for thin walled cylinders, with D/t of about 90, the effects of localized instabilities take over. The piping materials, temperature, modulus etc all have an effect.
Again, my question is: "At what point (i.e. a D/T ratio) do the local effects of bending take over and make a CAESAR-II analysis invalid ?"
Additionally, a reasonable person would ask, why doesn't CAESAR-II prohibit the running of an analysis when the D/t makes the model unstable/invalid....???????
MJC
RE: Schedule 10S & 5S Piping
Your desire for a simple answer to this complex issue i.e, "above this value X don't proceed," is reminiscent of how complex problems are viewed by management.
Regards,
XHPIPE
RE: Schedule 10S & 5S Piping
Richard Ay
COADE, Inc.