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Subject: Re: Modal cyclic symmetry ...something for the Wish List ?
Author: Gordon May
Date: 2002-06-06 07:23:00

I'm not aware of the MSHCopy command - is this new to ANSYS 5.6 or higher?
Anyway, I'm of the school of thought which says "I need to know how I want
to model the physics of the problem, not how to drive the tool". After all,
isn't this why Americans buy cars with automatic transmissions? You just
want to press the gas pedal to go faster, not worry about changing gears as
well...

In this case, the ability to select one of the sector faces and have ANSYS
automatically identify the matching face and take care of producing a
matching surface mesh would be the ideal. (I know this can be done as one
of Rolls-Royce's in-house analysis codes has such a capability)

Gordon May
Principal Technologist - Stress Methods
Compressor Key System
Tel.: +44 1332 2 44041
Fax: +44 1332 2 44874
mailto:gordon.may@r...

"If you speak to him of a machine for peeling a potato, he will pronounce it
impossible: if you peel a potato with it before his eyes, he will declare it
useless, because it will not slice a pineapple."
Charles Babbage

-----Original Message-----
Sent: 06 June 2002 11:27
To: 'xansys@yahoogroups.com'

List ?

Isn't there already a command for getting the exact mesh? MSHCopy or
something similar. Granted, it requires two steps.

JKT

> -----Original Message-----
> From: May, Gordon [mailto:Gordon.May@r...]
> Sent: 06. kes„kuuta 2002 12:40
> To: 'xansys@yahoogroups.com'
> Subject: RE: [xansys] Modal cyclic symmetry ...something for the Wish
> List ?

> Seems like VSWEEP should be modified (to include an option) so as to
> replicate the behaviour of AGEN when matching mesh patterns
> are required for
> cyclic symmetry...?

> Gordon May
> Principal Technologist - Stress Methods
> Compressor Key System
> Tel.: +44 1332 2 44041
> Fax: +44 1332 2 44874
> mailto:gordon.may@r...

> "If you speak to him of a machine for peeling a potato, he
> will pronounce it
> impossible: if you peel a potato with it before his eyes, he
> will declare it
> useless, because it will not slice a pineapple."
> Charles Babbage

> -----Original Message-----
> From: Prentice, Ian (GEAE) [mailto:Ian.Prentice@a...]
> Sent: 05 June 2002 16:04
> To: 'xansys@yahoogroups.com'
> Subject: RE: [xansys] Modal cyclic symmetry

> Like I said, the model must be in csys,1 (at least for v5.6).
> If a command
> is
> undocumented, you should ask yourself why.
> Even in csys,1 your model has some nodes which do not match -
> if you use
> vsweep
> you do not always get a matching mesh on the cut sides. To
> ensure a matching
> mesh use agen to overlay a copy of the original mesh on the
> opposite side,
> then
> merge the two areas together before vsweeping the volume.
> I noticed you are also doing 0 thru 4 nodal diameters- 0 can
> be done with
> symmetric bc's and 4 (in your case) with anti-symmetric,
> saving considerable
> computer time and filespace.
> Ian
> GEAE

> -----Original Message-----
> From: esa.prasad@p... [mailto:esa.prasad@p...]
> Sent: Wednesday, June 05, 2002 9:39 AM
> To: xansys@yahoogroups.com
> Subject: RE: [xansys] Modal cyclic symmetry

> HI,

> Here i am giving the macro which is down loaded from the
> web ofcourse
> from Ansys!! I thought atleast it should work COZ it is from
> ansys . But it
> is also not working and giving the same error.

> like

> No node matches Low node ##

> Can any one through some idea????????

> /clear
> !
> ! enter the preprocessor
> !
> /prep7
> !
> ! generate some keypoints
> k,1,10,25
> k,2,11,25
> k,3,13.45,27.45
> k,4,13.45,28.45
> k,5,13.45,36.45
> k,6,18.45,28.45
> k,7,18.45,27.45
> k,8,13.45,35.45
> k,9,18.45,36.45
> k,10,20.45,35.45
> k,11,20.45,38.45
> k,12,19.95,38.45
> k,13,18.95,36.45
> k,14,19.95,37.45
> k,15,10,12.5
> k,16,11,12.5
> k,17,0,35.45
> k,18,0,36.45
> k,19,18.45,35.45
> k,20,12.8,28.45,-9.3
> k,21,14.0,28.45,-8.9
> k,22,15.3,28.45,-6.5
> k,23,16.0,28.45,-3.8
> k,24,15.2,28.45,-2.8
> k,25,14.2,28.45,-3.7
> k,26,13.5,28.45,-5.9
> k,27,12.5,28.45,-7.85
> !
> ! make some straight lines
> l,19,10
> l,10,11
> l,11,12
> l,12,14
> l,13,9
> !
> ! make a few arcs
> larc,2,3,7,2.45
> larc,1,4,6,3.45
> larc,13,14,12,1
> !
> ! generate some areas
> a,15,16,2,1
> a,2,3,4,1
> a,7,6,4,3
> a,17,8,5,18
> a,5,8,19,9
> a,19,10,11,12,14,13,9
> !
> ! make a segmented spline through some keypoints
> flst,2,9,3
> fitem,2,20
> fitem,2,27
> fitem,2,26
> fitem,2,25
> fitem,2,24
> fitem,2,23
> fitem,2,22
> fitem,2,21
> fitem,2,20
> spline,p51x
> !
> ! make an area from the segmented spline
> flst,2,8,4
> fitem,2,24
> fitem,2,25
> fitem,2,26
> fitem,2,27
> fitem,2,28
> fitem,2,29
> fitem,2,30
> fitem,2,31
> al,p51x
> !
> ! extrude this area vertically
> vext,7,,,,7
> !
> ! make a local cylindrical coordinate system
> local,11,1,0,0,0,0,-90
> !
> ! copy a keypoint 45 degrees from keypoint 10
> kgen,2,10,,,,45
> !
> ! generate an arc
> l,10,36
> !
> ! drag some areas to generate some volumes
> vdrag,1,2,3,5,6,,48
> !
> ! generate a volume from keypoints
> v,17,8,46,18,5,45
> !
> ! glue all of the volumes together
> vglue,all
> !
> ! move the working plane to be aligned with 3 keypoints
> kwplan,-1,27,25,29
> kwpave,27,31
> !
> ! offset the working plane a bit in the Z direction
> wpof,,,1
> !
> ! generate a cylinder
> cyl4,,,1.3,,,,-4
> !
> ! subtract the cylinder from volume 4 to make a hole through it
> vsbv,1,4
> !
> ! set up the meshing controls on some of the lines
> lesize,3,,,3
> lesize,6,,,6
> lesize,7,,,6
> lesize,8,,,6
> lesize,11,,,3
> lesize,13,,,3
> lesize,14,,,3
> lesize,15,,,8
> lesize,16,,,8
> lesize,18,,,2
> lesize,21,,,10
> lesize,23,,,10
> lesize,22,,,3
> lesize,25,,,4
> lesize,26,,,4
> lesize,53,,,7
> lesize,54,,,3
> lesize,55,,,7
> lesize,57,,,6
> lesize,58,,,13
> lesize,59,,,3
> lesize,60,,,13
> lesize,61,,,6
> lesize,68,,,15
> lesize,69,,,15
> lesize,71,,,15
> !
> ! set up some element types
> !
> ! first, the linear bricks
> et,1,45
> ! then the quadratic bricks
> et,2,95
> ! followed by quadratic tets
> et,3,92
> !
> ! and now the dummy mesh elements
> ! the first one will be 6 node triangles
> et,4,200,5
> ! followed by 4 node quad
> et,5,200,6
> ! followed by 8 node quad
> et,6,200,7
> !
> ! start by meshing some of the areas
> !
> ! change to element type 4, 6 node triangle MESH200
> type,4
> ! set mesh key to map mesh
> mshkey,1
> ! mesh area 3
> amesh,3
> ! change to element type 5, 4 node quad MESH200
> type,5
> ! set mesh key to free mesh
> mshkey,0
> ! change the transitioning characteristics of the free
> ! mesh to be more gradual
> mopt,trans,1.5
> ! mesh area 6
> amesh,6
> ! change to element type 6, 8 node quad MESH200
> type,6
> ! mesh area 5
> amesh,5
> ! select the areas along the cut boundary that are meshed
> asel,s,area,,3
> asel,a,area,,5,6
> ! change to cylindrical coordinate system
> csys,11
> ! copy these areas about Z axis 45 degrees
> agen,2,all,,,,45
> ! switch back to global cartesian coordinate system
> csys
> ! select everything
> allse
> ! merge coincident keypoints
> numm,kpoi,.001,.001
> ! change to element type 5, 4 node quad MESH200
> type,5
> ! mesh area 44
> amesh,44
> !
> ! mesh all of the volumes
> !
> ! change to element type 1, SOLID45
> type,1
> ! sweep mesh volume 6
> vsweep,6
> ! sweep mesh volume 7
> vsweep,7
> ! change to mapped meshing
> mshkey,1
> ! map mesh volume 2
> vmesh,2
> !
> ! change to element type 2, SOLID95
> type,2
> ! map mesh volume 3
> vmesh,3
> !
> ! change to element type 3, SOLID92
> type,3
> ! change to free meshing
> mshkey,0
> ! free mesh volume 5
> vmesh,5
> !
> ! now map the transition elements between the solid
> ! bricks and the solid tetrahedral elements
> !
> ! change to element type 2, SOLID95
> type,2
> ! change to free meshing
> mshkey,0
> ! tell ANSYS to mesh SOLID95 in tetrahedral form
> mshape,1,3d
> ! mesh volumes 8 and 9
> vmesh,8,9
> !
> ! change the SOLID95 tetrahedral elements to SOLID92
> tchg,95,92,3
> !
> ! all done generating and meshing the volume
> !
> ! turn type numbers on
> /pnum,type,1
> ! turn numbering off so that only colors are shown
> /num,1
> ! turn working plane symbol off
> wpstyle,,,,,,,,0
> ! set up the view so we can see what we have made
> /view,1,-.226,.36,.9
> ! plot the elements
> eplo
> !
> !

> !second macro for cyclic symmetry
> !

> ! enter the preprocessor
> /prep7
> !
> allse
> ! generate some material properties
> mp,ex,1,30e6
> mp,nuxy,1,.3
> mp,dens,1,.00077
> !
> ! make components of the low and high edge pairs
> ! low set first (low in csys5 y direction)
> allse
> asel,s,area,,1,6
> nsla,s,1
> csys,5
> nrot,all
> cm,nodeset1,node
> !
> ! high set second
> asel,s,area,,10,11
> asel,a,area,,14,21,7
> asel,a,area,,25,43,18
> nsla,s,1
> nrot,all
> cm,nodeset2,node
> allse
> ! generate the cyclic sector with loads
> cycgen
> !
> ! constrain the model on the upper rim
> csys,5
> nsel,s,ext
> nsel,r,loc,x,20.45
> d,all,all
> allse
> !
> !
> ! enter the solver to do the analysis
> /solu
> ! define this as a modal analysis problem
> antype,2
> eqslv,spar
> mxpand,20
> modopt,lanb,20,,,,off,,2
> !
> allse
> ! Use this macro as follows:
> !
> !
> CYCSOL,ndmin,ndmax,nSector,LOW,[HIGH],tol,kmove,kpairs,sysnum
> !
> ! where: ndmin - lowest nodal diameter in range
> ! ndmax - highest nodal diameter in range
> ! nSector - number of sectors in full circle
> ! LOW - the LOW node component name (or
> MULTICYC)
> ! HIGH - the HIGH node component
> name (if any)
> ! tol - Tolerance for CECYC command
> ! kmove - If 1, move nodes to be coincident
> ! kpairs - If 1, print pairs of matching nodes
> ! sysnum - Cylinderical coordinate system for
> ! cyclic symmetry (1 by default)
> ! declare this to be a cyclic modal symmetry problem
> cycsol,0,4,8,'nodeset1','nodeset2',.001,,,11
> !
> ! enter the postprocessor
> !/post1
> ! tell ANSYS to expand the graphical image
> !expand,8,modal,1,5,45
> ! or depending on the nodal diameter you can use /expand
> ! /expand,nrepeat,MODAL,ndiam,icsys,sectorangle,,phase
> !/expand,8,modal,1,5,45
> !set,first
> !plns,u,sum
> !

> regards
> Narasimha Prasad Esa
> Alstom Power Technology Center
> United Kingdom

> "Prentice, Ian (GEAE)" on 06/05/2002
> 11:55:03 AM

> To: "'xansys@yahoogroups.com'"
> cc:

> Subject: RE: [xansys] Modal cyclic symmetry

> The model must be in CSYS,1
> Ian
> GEAE

> -----Original Message-----
> From: esa.prasad@p... [mailto:esa.prasad@p...]
> Sent: Wednesday, June 05, 2002 6:41 AM
> To: xansys@yahoogroups.com
> Subject: [xansys] Modal cyclic symmetry

> Hi,

> I am doing cyclic symmetry - modal analysis on nozzle. I have
> created High
> and Low end node components ( these nodes are in say 11
> coordinate system
> which is cylindrical) and also i checked the matching nodes
> coordinates (
> that is cyclic sector angle between corresponding nodes on
> two sides) , the
> cordinates matches.

> now i am trying to use cycsol command ( ansys5.6) it is giving the
> following error.

> No node matches Low node ##

> it is listing error for all nodes in Low and High componets,
> that means it
> is not applying cyclic symmetry ( or CE s).

> Can any one have any idea why it is happening so, what must
> be going wrong
> in this case?

> is there any undocumented field in CYCSOL command????????

> i am using cycsol,0,0,48,'low','high',0.1,0,0,11

> i am having doubt about last field which specify coordinate
> system! which
> is undocumented??

> thanks to all

> Narasimha Prasad Esa
> Alstom Power Technology Center
> United Kingdom.

Posts possibly associated with message #38541AuthorDateScore
38539Re: Modal cyclic symmetry ...something for the Wish List ?Gordon May2002/06/06 
38540Re: Modal cyclic symmetry ...something for the Wish List ?Juha Tyllinen2002/06/06 
38541Re: Modal cyclic symmetry ...something for the Wish List ?Gordon May2002/06/06 
38542Re: Modal cyclic symmetry ...something for the Wish List ?Ian Prentice2002/06/06 
38546Re: Modal cyclic symmetry ...something for the Wish List ?Juha Tyllinen2002/06/06 
38552Re: Modal cyclic symmetry ...something for the Wish List ?Dan Bohlen2002/06/06 
38558Re: Modal cyclic symmetry ...something for the Wish List ?Gordon May2002/06/06