Stress in GRE Pipe at Support

[denniskb]

I have been trying to determine the local stresses in GRE pipe at the pipe support location and wondered whether COADE may have identified a method to do this.

The calculations I have found to date do not fit the typical GRE solution of glueing a 120° to 180° GRE saddle to the pipe at the support.

Further the results obtained from the varoius methods vary widely.

My original query is at thread327-119705


Dennis Kirk Engineering

http://www.ozemail.com.au/~denniskb

 

[richay]

Unfortunately we (COADE) have not encountered a published method to determine local stresses at pipe support locations in GRE pipe.

However, we do have a contact on the B31.3 FRP committee who has stated he is willing to act as resource for this sort of evaluation. E-mail me at COADE and I'll pass his information along to you.

Richard Ay
COADE, Inc.

 

[denniskb]

Richard,

Thank you for that information.

I have set up an Excel calculation using the method proposed in "Overcoming the Metal Mindset in FRP Pipe Design" and Roark's Table 17, Case 20.

The Excel file can be downloaded from my website at

http://www.ozemail.com.au/~denniskb

by following the link to "Design Calculations", submit the form (with name please) then selecting "Miscellaneous Files" at the bottom of the page.

I would like to get some feedback of whether this method "Ring Stiffener" is really appropriate.
- I have set up the calculation at top, side and bottom of the pipe as a rough means of determining how far round a partial saddle might need to go.
- I have serious doubts about the deflections calculated?
- I have been a little creative with the deflections for the stiffened pipe.

The "Saddle Stiffener" worksheet is the ISO 14692 method.

I will pass this on to a couple of GRE pipe manufacturers to see if I can get some input from them.


Dennis Kirk Engineering

http://www.ozemail.com.au/~denniskb