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Subject: Re: Modal cyclic symmetry ...something for the Wish List ?
Author: Gordon May
Date: 2002-06-06 11:49:00

Many thanks Dan!

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 14:52
To: 'xansys@yahoogroups.com'

List ?

WISH GRANTED .... just not documented....

From Sheldon's site
http://ansys.net/ansys/?mycat=search&mytype=All&mystring=vsweep

MOPT

MOPT,VSSM,OFF
Below describes an option for controlling "node relaxation" when using the
VSWEEP command. This is needed when using VSWEEP with volumes that are
axisymmetric, where you might have previously used VROT. The purpose of this
option is to ensure that the nodes on opposite sides of the volume are
positioned with identical radial and axial coordinates. When you create
couples
for cyclic symmetry, your nodes will match up precisely.
By default node relaxation is turned on. If you see that the source and
target
area are identical, you can issue the command.
If you have it turned off and you try to sweep a volume that changes in
cross
section, then you'll probably get bad quality elements. [command available
in
5.5.1 and above]

-----Original Message-----
Sent: Thursday, June 06, 2002 5:40 AM
To: 'xansys@yahoogroups.com'

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-----
Sent: 05 June 2002 16:04
To: 'xansys@yahoogroups.com'

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-----
Sent: Wednesday, June 05, 2002 9:39 AM
To: xansys@yahoogroups.com

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:

The model must be in CSYS,1
Ian
GEAE

-----Original Message-----
Sent: Wednesday, June 05, 2002 6:41 AM
To: xansys@yahoogroups.com

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 #38558AuthorDateScore
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