Local stresses in pipe at support 1

[men5muw]

I am trying to analyse the local stresses in pipe (24" sch. 20) at a support without pipe shoe. I have used the euqations shown in the attached file. These equations are taken from "Formulas for stress and strain" by Roark.
In 5th edition of the book, the coefficient for 3rd equation is "-1" while in 6th edition it is -1.56. I wonder if any body have the original paper these equations have been taken from and confirm which coefficient is correct.

Could some body suggest any other method for analysing local stresses at pipe support.

Thanks and regards

Waheed

 

[men5muw]

I am still waiting for a reply from some one

Waheed

 

[nickelkid]

The Piping Handbook suggests the attached

 

[rconner]

Pipe-on-supports and specifically the rather complex localized interactions of pipe at support locations have been studied by many researchers over a very long time frame. I know some of the earlier, and I think then quite innovative, researchers (even before the days of modern strain gauges/indicators) even glued long thin wooden sticks (sort of glorified popsicle sticks) to steel pipe walls to sort of amplify for direct measurement/determination even very slight pipe wall movements/deformations.
Many years later (but still a quarter century ago!) I assisted in some laboratory work for a rather detailed research program that looked at the specific wall response of another type of metallic pipe material, utilizing at least more expensive/at the time modern if not at least equally effective instrumentation etc.!
In any case, I believe an outgrowth of work over many decades involving at least steel water pipes is now ensconced in Chapter 7 “Supports for Pipe” of AWWA Manual M11, “Steel Pipe – A Guide for Design and Installation” if this would be of interest to you.

 

[vpl]

men5muw

Part of your question was "did anyone have the original paper."

Does Roark provide a reference to the papers (most books do). If you post the particular reference it might help getting a copy.

Did you contact the publisher and ask why the value changed? Often a publisher will forward this type of question to the author(s). That would give you the most authoritative answer.

Patricia Lougheed

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[carthago]

I believe the European Code EN 13480 - part 3 has a lengthy method (paragraph 11 ) it refers also to WRC 107, 297 and PD5500,..)

 

[JohnBreen]

We used to use the Kellogg Method (from their in-house design standard) but now use the FE/Pipe software (have a look at the Paulin Research Group web site). The FE/Pipe software has rather conclusively shown the Kellogg method to be wanting. The WRC bulletins are limited (and often the limits are ignored) and they are really an approximation.

 

[JohnBreen]

and

 

[JohnBreen]

well..........and the attachment is the Kellogg method (if I can get this attachment thing right). I would like to read the EN 13480 method too so I will go and have a look at that.

Much easier to use FE/Pipe suite of software so maybe I am REALLY getting lazy in my olde age

John

 

[rconner]

I wasn't exactly sure what "original" paper or how far back the original poster was wanting, but I noticed that (I guess amazingly to me) a quite lengthy report of a testing program 67 years ago involving at least some various loadings on steel shells at the University of Illinois (Urbana)I thought I remembered has actually been "digitized" and is now available at

https://www.ideals.uiuc.edu/bitstream/2142/4123/3/engineeringexperv00000i00331.pdf!

I think even quite earlier in that century other testing was conducted, even with cast iron (pipe) shells loaded on supports, and even involving e.g. buried earth simulations and other conditions at Iowa State College (later to become ISU, my alma mater) and later some maybe also at U. Illinois-Champaign Urbana.
[You may see some other testing etc. references noted e.g. on page 57 of the book that can be viewed in part at

http://books.google.com/books?id=Z3...&hl=en&sa=X&oi=book_result&resnum=5&ct=result

]