FRP stress analysis

I am interesting to know if there is any criteria to determine or select which FRP piping must be subjected to stress analysis. I mean, which critical conditions has to have the FRP pipe in order to decide that needs to have stress analysis.

I am working in an offshore platform project and we have 12” pipes with operating temperature of not more than 65 C (hot water).

What load cases have to be analyzed for FRP pipes? Where do I can find more information about FRP stress analysis?

Thank you
cristina_fys

For a quick understanding on FRP/GRP design and Stress Analyis I would suggest AWWA M 45.

IS0 14692 (pART 1-4) is an extensive code again for GRP piping systems.

Be aware of shorter spans, local supporting, different Modulus in axial/ hoop direction. Higher expansion rates than steel and joints (restrained/unrestrained).

Dear cristina,

Be shure to analyse first of all the OPE case including the axial expansion due to temperature and pressure. Codes compliance can be performed using Caesar II based on BS7159 or UKOOA codes.

The Caesar II manual provides some basic information on FRP stress analysis, but be shure to get the material prop. and allowables from the piping material vendor. Some technical data can also be found on the vendor hompages, e.g. www.futurepipe.com.

Best Regards,
Veit Bockemühl
www.esn-gmbh.com
www.pipestressanalysis.com

Thats a very good point from Mr Veit. In a project where you are involved with GRP piping, make sure you involve your prospective GRP Vendors from a very earlier stage as the product properties can be differ from vendor to vendor.
Most of the execution approches are to include the Stress Analysis of GRP portion in the GRP vendor scope or a specialist agency.

Another excellent Vendor site is WWW.SARPLAST.COM.

You can also refer WWW.ADPF.AE, AMIANTIT (http://www.afilpipe.com/)and others.

Christina,

There are some significant features of FRP stress analysis.

Let's get down to the throretical part a little bit.

FRP pipes are orthotropic and need nine material constants for analysis. However for a stick element, they can roll down to four.

The failure theories that are applicable for isotropic materials are not valid for orthotropic materials.Tsai-Hill ( a modification of the Von Mises criteria for isotropic materials)and Tsai-Wu ( stress tensor polynomial) theories address the failure mechanism for these materials.

If you are inetersted . kindly provide youe-email address and I can send you some documents on FRP analysis.

Thanks and Regards

Anindya

Anindya, I'm very interested, please send the documents to cristina_fys@cantv.net

Regards

Hi cristina

One very helpful FRP piping manufacturer who has an excellant FRP design guide is RPS. (www.rps.ca). May pay to look at their website (I think you can download their design guide from this site). The design guide has some tips on carrying out FRP pipe stress analysis.

Hi Anindya

I also have to carry out stress analysis on FRP piping occasionally, and am always pretty nervous as I know what I don't know about FRP piping. Could you also forward to me the documents you mentioned to cristina?

My email address is: krobo0@lycos.com.

I would greatly appreciate it. Thanks

CHRISTINA AND ITCHY,

Both of you will get the documents shortly at your e-mail addresses.

Regards

Miss Itchy,

There was a delivery failure at your e-mail address due to lack of space in your mail box.

Regards

Dear Anindya,

I would also be interested in the a.m. documents,
my e-mail address is vb@esn-gmbh.com.

Thanks in advance & best regards,
Veit Bockemühl
www.esn-gmbh.com

Anindya,

Since so many people are interested, if you want, send them to me and I'll put them up on the website with a link to them from this thread.

Anindya

You're right my email box was pretty full, all cleaned out now, Can you resend? (or of you have them to Richard at Coade anyway don't worry as I'll find the link when he posts it).

Much appreciated.

Dear Anindya,
I am very interested. Please send me a copy of the said document at"manoj_sarkar@rediffmail.com".

Regards,

Richard,

I have sent the documents to you at your e-mail address.

Regards

Here are the documents:

- TSAI_WU_TSAI_HILL.pdf
- FRP_PIPING_PROBLEMS.pdf
- FAILURE_CRITERIA_ANISOTROPIC_MATERIALS.pdf

Anindya, can you offer any information as to the source of these documents?

Ray,

I downloaded these documents from the net over a period of time.I cannot recall the sites from which I downloaded these documents.My memory clock has to turn little back and I will come back to you asap.

Regards

Dear all,

This thread has been a long time, but if anyone is still keeping the documents, please send me, the above link died

My email is progiangbk@gmail.com

Thanks in advanced!

the link is not working..somebody have downloaded and still keep it, please share to me just for reference.

My email: lelaki.aku@gmail.com

Thanks a lot!

Dear Richard

Links as mentioned are not working right now,may be since a long time this thread is worked in this forum,however it is requested to you can you upload once again or can anyone send my email address.

davesnehal20@gmail.com

Thanks in advance.

Regards
SND

Sorry, those were posted 7 years ago. I can no longer find these documents on my machine.

Dear Richard & Anindya

With ref. to above conversation for the same subject , I request you to please share material on my personal id paresh_tulankar@rediffmail.com

Thanks & Regards
Paresh Tulankar
India

hi to all of you

request you all if you could share the same documents to me at
nitinlonkar@rediffmail.com

hello fellow stressers,

kindly provide me also with the frp information mentioned by anindya....My email ad is tibor121774@yahoo.com...I'm also interested to study FRP Stress analysis..Many thanks in advance...

Cheers,

Hi to all of you

could you please share the same documents to me too at: daly_toulousain@hotmail.fr

Cheers

Dear All,

Anyone could share documents about FRP piping problems please?

Thanks in advance

Hi everybody, I'd like to have the documents too, please share them with me at caligola2000@email.it
Many thanks

Dear Expert,

I found this criteria in one of the FRP Handbook by the Vendor.

STRESS ANALYSIS NOT REQUIRED
• Pipes ≤ 2 “
• Non restrained joints (Double Bell Coupler)
• Design pressure below 1 barg (drains)
• System with anchor / thrustblocks


Need your opinion as why stress analysis is not required for the non restrained joints (double bell coupler)?

I have this issue that the Contractor has installed a non-restrained GRP pipe and the Client wants to check this with the stress analysis.

Thank you very much and your quick reply will be highly appreciated.

Someone mentioned using RPS as a vendor for FRP and conducting stress analysis on their piping. My company completed a large job last year in which I conducted stress analysis of over 100 RPS FRP lines. Their documentation explaining all areas of their FRP is very well written and they have great customer support from a stress analyst POV.

One thing that was surprising to me however is that they recommend completing stress analysis on their FRP using B31.3 code. They provide all of the necessary properties including the allowable stresses and also documentation to show a safety factor of 6 (if memory is correct) in their design.

Ultimately, the vendor should know best what to do with their pipe. So as others have stated, figure out what information is needed to do your stress analysis and make sure to receive all of it from the vendor before starting any work. If it is a large job, put off the FRP in the beginning to make sure you can wrap your brain around everything from the vendor and give yourself time to communicate back and forth. I'm a few weeks into this process right now with a different vendor and it can be tedious. Especially if there is a language barrier.

Dmitriy

the basic theory papers were from Stephen W. Tsai,
A General Theory of Strength for Anisotropic Material
Strength Characteristics of composite materials.

Read those twe paper will help you

Hello everyone! I'm trying to run an analysis using the UKOOA standard for FRP material. My question is about the results of stress analysis. When used these above conditions, for load case 3 (Exp) L3 = L1-L2, is mentioned "in the code stress check processed." What can be wrong and should be revised.

and it is usual or should be used to UKOOA for this evaluation with the FRP materials?

Thank you!


The following results

LOAD CASE DEFINITION KEY

CASE 1 (OPE) W+T1+P1
CASE 2 (SUS) W+P1
CASE 3 (EXP) L3=L1-L2


Piping Code: UKOOA = UKOOA (1994)


CODE STRESS CHECK PASSED : LOADCASE 1 (OPE) W+T1+P1

Highest Stresses: ( KPa ) LOADCASE 1 (OPE) W+T1+P1
OPE Stress Ratio (%): 31.6 @Node 60
OPE Stress: 2857.5 Allowable: 9034.3
Axial Stress: 1510.9 @Node 8
Bending Stress: 2009.9 @Node 60
Torsion Stress: 200.9 @Node 9
Hoop Stress: 5144.7 @Node 50
3D Max Intensity: 3767.6 @Node 20

CODE STRESS CHECK PASSED : LOADCASE 2 (SUS) W+P1

Highest Stresses: ( KPa ) LOADCASE 2 (SUS) W+P1
CodeStress Ratio (%): 30.6 @Node 20
Code Stress: 2765.5 Allowable: 9034.3
Axial Stress: 1510.9 @Node 8
Bending Stress: 1872.6 @Node 20
Torsion Stress: 57.2 @Node 9
Hoop Stress: 3898.9 @Node 50
3D Max Intensity: 3750.1 @Node 20

NO CODE STRESS CHECK PROCESSED: LOADCASE 3 (EXP) L3=L1-L2

Highest Stresses: ( KPa ) LOADCASE 3 (EXP) L3=L1-L2
CodeStress Ratio (%): 0.0 @Node 49
Code Stress: 648.9 Allowable: 0.0
Axial Stress: 0.0 @Node 8
Bending Stress: 968.5 @Node 49
Torsion Stress: 143.8 @Node 9
Hoop Stress: 1291.6 @Node 49
3D Max Intensity: 1000.7 @Node 49

UKOOA evaluates the state of stress rather than segregating sustained and expansion (collapse and fatigue failures, respectively). So every operating state should be checked.
CAESAR II includes your L1-L2 case for use in diagnosing problems.