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Subject: Re: Piping analsysis
Author: MAHESHWAR D UMA duma_maheshwar@
Date: 2001-07-10 06:12:00

Dear ANSYS users

I have posted the following problem for which I need
more suggestions.

Request all the ANSYS gurus to guide me.

Thanks

> 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 #25718AuthorDateScore
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