XANSYS Message: 25663 [Go back to message list]
[bookmark on del.icio.us]
No rating yet
Rate item:

Subject: Re: Piping analsysis
Author: Pollmanns, Josef josef.pollmanns@
Date: 2001-07-09 05:18:00

Hello,

you have to check, how much you can compress the wiremesh. This way should
be greater than the displacement difference between the two pipes. Than you
can go to suggestion a.

Josef

-----Ursprüngliche Nachricht-----
Von: MAHESHWAR D UMA [mailto:duma_maheshwar@y...]
Gesendet am: Montag, 9. Juli 2001 10:55
An: xansys
Betreff: Re: AW: [xansys] Piping analsysis

Joseph

Thanks for your suggestions.

Can you please elaborate your suggestions ? How do we
compensate the stiffness ?

Thanks

--- "Pollmanns, Josef" wrote:
> Hello,

> - Thermal analysis

> 1. calculation without the connection between the
> pipes
> 2. look to the displacements between the pipes and
> compare them with the
> displacement, the mesh can copensate
> a. the wiremesh can compensate the displacement
> between the pipes
> define the stiffness of the mesh ant take it into
> account in your analysis
> b. the wiremesh can not compensate the displacement
> if that is the case, ????

> - Pressure analysis

> see thermal analysis

> - frequencies

> you can also take into account the stiffness of the
> wiremesh, but I am not
> sure, if it realy help in comparison with a rigid
> coupled model.

> Josef

> -----Ursprüngliche Nachricht-----
> Von: MAHESHWAR D UMA
> [mailto:duma_maheshwar@y...]
> Gesendet am: Montag, 9. Juli 2001 08:50
> An: xansys
> Betreff: Re: [xansys] Piping analsysis

> Dear ANSYS users

> I apologise for not attaching a sketch on my query.
> However I wish to give some more details on my query
> and request your inputs.

> A double wall tube has inner and outer tubes
> separated
> by a small gap. I have taken a U-shape pipeline of
> double wall tube cross section and used PIPE16/18
> elements for both these tubes.

> I am interested in finding natural frequencies of
> the
> system. How to combine both inner and outer tubes ?
> I
> have coupled the tubes at all the nodes but this is
> resulting higher stresses at the tube bends. Also
> the
> natural frequencies are not matching with that of
> Code/theoritical values..

> Please share your experience on similar problems and
> suggest.

> Best Regards

> > > > Dear ANSYS users

> > > > I am analyzing double wall piping as a part
> of
> > my
> > > > thesis work.

> > > > The double wall tubing consists of inner and
> > outer
> > > > tubes of different thicknesses and are
> subjected
> > to
> > > > different pressures and temperatures. A small
> > gap
> > > > between the outside dia of the inner tube and
> > inner
> > > > dia of outside tube is maintained by wire
> > > > winding/spacer on the outside diameter of
> inner
> > > > tube.

> > > > I have used PIPE16/18 elements to model both
> the
> > > > inner
> > > > and outer tubes. I coupled the inner and
> outer
> > > > tubes
> > > > in such a way that the tubes can expand along
> > the
> > > > tube
> > > > and rotate about the tube. The coupling is
> given
> > at
> > > > the start and end of the straight tubes.

> > > > I find very high stresses at the tube bends
> > which
> > > > are
> > > > not matching with those of classical
> > solutions/Codes
> > > > such as ANSI B31.3 etc.

> > > > Is that the high stresses are caused due to
> the
> > > > coupling ? Then how to model the tubes ? I am
> > > > interested in doing both the modal and
> > structural
> > > > analysis.

> > > > Can anybody suggest the better method of
> > analyzing
> > > > the
> > > > above ?.

> > > > Maheshwar duma
> > > > PG Student

> > > [Non-text portions of this message have been
> > removed]

> > Dan Bohlen Phone: (513) 243-4645 /
> Dial
> > Comm [8*332-4645]
> > Stress Analyst Email: dan.bohlen@a...

=== message truncated ===

Posts possibly associated with message #25663AuthorDateScore
25552Piping analsysisMAHESHWAR D UMA duma_maheshwar@2001/07/04 
25555Re: Piping analsysisPollmanns, Josef josef.pollmanns@2001/07/04 
25569Re: Piping analsysisMAHESHWAR D UMA duma_maheshwar@2001/07/05 
25571Re: Piping analsysisDiego Gorriz2001/07/05 
25578Re: Piping analsysisDan Bohlen2001/07/05 
25622Re: Piping analsysisMAHESHWAR D UMA duma_maheshwar@2001/07/06 
25626Re: Piping analsysisPollmanns, Josef josef.pollmanns@2001/07/06 
25657Re: Piping analsysisMAHESHWAR D UMA duma_maheshwar@2001/07/09 
25658Re: Piping analsysisPollmanns, Josef josef.pollmanns@2001/07/09 
25662Re: Piping analsysisMAHESHWAR D UMA duma_maheshwar@2001/07/09 
25663Re: Piping analsysisPollmanns, Josef josef.pollmanns@2001/07/09 
25717Re: Piping analsysisMAHESHWAR D UMA duma_maheshwar@2001/07/10 
25718Re: Piping analsysisMAHESHWAR D UMA duma_maheshwar@2001/07/10 
25719Re: Piping analsysisPollmanns, Josef josef.pollmanns@2001/07/10