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[Noob][Help] No nodes defined

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arpit22x

Aerospace
Mar 6, 2013
8
IN
Dear members, just started learning Ansys, I made a program which contains a rectangular plate with two circles (have different material). I want to analyse the buckling by putting the compressive load on one edge and a fixed support on another edge.

When I run the program, it says, no nodes defined, I am attaching the txt file, please tell me where to modify.

Thanks!!

Arpit
 
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Ah ok. You've defined your model geometry but you haven't meshed your model, hence the "no nodes defined" message.

Issue an ALLSEL command and then an AMESH command prior to the /SOL near the bottom of your code. Then check your mesh and then re-run.


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The model has either run unsuccessfully or it cannot find the results file. Check in your working directory for the existence of a .rst file, but you need to check the output to establish exactly what the error message is.

For good practice you should set the filname at the top of your code as well as some other standard commands. Put these commands at the top of your code and then re-run:

finish
/clear,nostart
/filnam,mymodel

Your structural results file will be "mymodel.rst"

At the bottom of your code after the SOLVE command put a SAVE command. This will create a database file mymodel.rst.






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Sorry, the last line should read:

"At the bottom of your code after the SOLVE command put a SAVE command. This will create a database file mymodel.db."




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Hi Arpit,
I have run your input file. At first I thought that the problem was because bad mesh, so I changed the mesh.
But I found that the mesh was not the problem.
We just need to merge you keypoints and nodes for your model using command:
nummrg,kp
nummrg,node
Hope this helps!
 
Can you please run this code and tell me where am I doing wrong.... Its the problem in merging but I don't know how to eliminate this. Its throwing these kinds of series of errors:
--------------------------------------------------------
Triangle element 2 has an aspect ratio of 1.E+20, which exceeds the
error limit of 1000000.
*** ERROR *** SUPPRESSED MESSAGE CP = 7.769 TIME= 15:54:52
Triangle element 1976 has a zero or negative determinant of the
Jacobian matrix at one of its sampling locations. Midside nodes, if
any, may be poorly positioned.
*** WARNING *** CP = 7.878 TIME= 15:55:02
Due to merging of lines 10 and 18,
Nodes 484 through 530 may no longer be associated with any line.
--------------------------------------------------------------

Please help, If these errors are due to sizing, then please tell me what should I put the sizing values for elements and others.
!*
/PREP7
!*
ET,1,PLANE183
!*
KEYOPT,1,1,0
KEYOPT,1,3,3
KEYOPT,1,6,0
!*
ET,2,PLANE183
!*
KEYOPT,2,1,0
KEYOPT,2,3,3
KEYOPT,2,6,0
!*
!*
R,1,5e-3,
!*
!*
R,2,5e-3,
!*
!*
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,1,,3.575e9
MPDATA,PRXY,1,,0.349
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,2,,80e9
MPDATA,PRXY,2,,0.22
BLC4,0,0,10e-3,140e-3
CYL4,5e-3,35e-3,17.5e-4
CYL4,5e-3,105e-3,17.5e-4
FLST,3,2,5,ORDE,2
FITEM,3,2
FITEM,3,-3
ASBA, 1,P51X
CYL4,5e-3,35e-3,17.5e-4
CYL4,5e-3,105e-3,17.5e-4
!*
/NOPR
KEYW,PR_SET,1
KEYW,PR_STRUC,1
KEYW,PR_THERM,0
KEYW,PR_FLUID,0
KEYW,PR_ELMAG,0
KEYW,MAGNOD,0
KEYW,MAGEDG,0
KEYW,MAGHFE,0
KEYW,MAGELC,0
KEYW,PR_MULTI,0
KEYW,PR_CFD,0
/GO
!*
/COM,
/COM,Preferences for GUI filtering have been set to display:
/COM, Structural
!*
!*
KEYOPT,1,1,1
KEYOPT,1,3,3
KEYOPT,1,6,0
!*
KEYOPT,2,1,1
KEYOPT,2,3,3
KEYOPT,2,6,0
!*
FLST,5,2,5,ORDE,2
FITEM,5,1
FITEM,5,-2
CM,_Y,AREA
ASEL, , , ,P51X
CM,_Y1,AREA
CMSEL,S,_Y
!*
CMSEL,S,_Y1
AATT, 2, 2, 2, 0,
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
!*
CM,_Y,AREA
ASEL, , , , 4
CM,_Y1,AREA
CMSEL,S,_Y
!*
CMSEL,S,_Y1
AATT, 1, 1, 1, 0,
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
!*
SMRT,6
SMRT,1
MSHAPE,1,2D
MSHKEY,0
!*
FLST,5,3,5,ORDE,3
FITEM,5,1
FITEM,5,-2
FITEM,5,4
CM,_Y,AREA
ASEL, , , ,P51X
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
!*
AMESH,_Y1
!*
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!*
NUMMRG,NODE, , , ,LOW
NUMMRG,KP, , , ,LOW
FINISH
/SOL
!*
ANTYPE,1
!*
BUCOPT,LANB,10,0,0,
/STATUS,SOLU
SOLVE
 
Edit: In the last post, I forgot to apply the loading. but the errors are coming in the way of merging only, please suggest any way to merge them appropriately.

Thanks in advance, its my starting of learning Ansys, your help will be precious for me.
 
Hi Arpit,
The merging process creates only warning(s) not error, so I think you can proceed with your model.
One suggestion, you'd better check the model merging (issue nummrg command twice) to make sure that all nodes and kpoints are merged completely.

 
@nakaAnsys
It's giving these errors along with warnings...


*** ERROR *** SUPPRESSED MESSAGE CP = 5.351 TIME= 12:33:07
Triangle element 1978 has a zero or negative determinant of the
Jacobian matrix at one of its sampling locations. Midside nodes, if
any, may be poorly positioned.
 
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