contact problem

[samuelecorsi]

hi!
i've got some problem with contact manager to create contact elements.
i'm studying a simple T-stub connected to a rigid support with bolts.
in the bolt zone, I made contact elements.
in linear analysis, ansys converges!
when i choose a non linear geometric analysis solution, ansys doesn't converge because contact elements doesn't work.
Do you know if non linear analys presents some different parameteres to setting in contact manager?
thanks a lot!
have a nice day

ps. sorry for my english

 

[maheshh]

Have one more question I would like to add about modeling methodology about contact problems:

I can see most of the folks here talk about creating contact/target elements on the surfaces which will interact in the problem. Am working whether this is necessary? Through contact manager, if you specify target and contact faces, and type of contact (node-surface, surface-surface), then Ansys does this for you. Isn't this good enough? Why create elements yourself?

Thanks in advance.
Mahesh

 

[Stringmaker]

Samuel,
What type of error messages are you getting? Even if your solution does not converge you can still go into /POST1 and view load step 999999 to see what is happening exactly with your model. Hopefully this helps you troubleshoot it yourself. You need to provide a little more info in order to receive positive feedback from users on here.

-Brian

 

[samuelecorsi]

hi Mahesh & Brian, thanks for your replies but, i've just tried things you told me.

For Mahesh: i know that with contact manager ansys automatically creates contact elements and i usually work in this way.
For Brian: nothing errore message. ansys shows a beautiful pop up writing "solution is done!", but when i require the deformed shape, i can see a compenetration phenomenon.

if you want to try, i can send you a little example of my problem. you've to paste on the command window. there's a compenetration phenomen but if you disattivate non linearities properties, the problem should go in a good way.



/PREP7
ET,1,SOLID187
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,1,,355
MPDATA,PRXY,1,,0.3
BLOCK,0,10,0,60,0,5,
wpoff,0,0,6
BLOCK,0,10,0,40,0,10,
wpoff,0,40,0
BLOCK,0,10,0,20,0,10,
FLST,2,2,6,ORDE,2
FITEM,2,2
FITEM,2,-3
VGLUE,P51X
FINISH
/SOL
FINISH
/PREP7
MSHKEY,0
MSHAPE,1,3d
FLST,5,3,6,ORDE,3
FITEM,5,1
FITEM,5,-2
FITEM,5,4
CM,_Y,VOLU
VSEL, , , ,P51X
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
FINISH
/SOL
FLST,2,2,5,ORDE,2
FITEM,2,1
FITEM,2,9
/GO
DA,P51X,ALL,0
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,30
FINISH
/PREP7
CM,_NODECM,NODE
CM,_ELEMCM,ELEM
CM,_KPCM,KP
CM,_LINECM,LINE
CM,_AREACM,AREA
CM,_VOLUCM,VOLU
MP,MU,1,0.7
MAT,1
MP,EMIS,1,7.88860905221e-031
R,3
REAL,3
ET,2,170
ET,3,174
KEYOPT,3,9,0
KEYOPT,3,10,1
R,3,
RMORE,
RMORE,,0
RMORE,0
ASEL,S,,,7
ASEL,A,,,19
CM,_TARGET,AREA
TYPE,2
NSLA,S,1
ESLN,S,0
ESURF
CMSEL,S,_ELEMCM
ASEL,S,,,2
CM,_CONTACT,AREA
TYPE,3
NSLA,S,1
ESLN,S,0
ESURF
R,4
REAL,4
ET,4,170
ET,5,174
KEYOPT,5,9,0
KEYOPT,5,10,1
R,4,
RMORE,
RMORE,,0
RMORE,0
TYPE,4
ESEL,S,TYPE,,3
NSLE,S
ESLN,S,0
ESURF
TYPE,5
ESEL,S,TYPE,,2
NSLE,S
ESLN,S,0
ESURF
ALLSEL
ESEL,ALL
ESEL,S,TYPE,,2
ESEL,A,TYPE,,3
ESEL,R,REAL,,3
ESEL,ALL
ESEL,S,TYPE,,2
ESEL,A,TYPE,,3
ESEL,R,REAL,,3
ESEL,A,TYPE,,4
ESEL,A,TYPE,,5
CMSEL,A,_NODECM
CMDEL,_NODECM
CMSEL,A,_ELEMCM
CMDEL,_ELEMCM
CMSEL,S,_KPCM
CMDEL,_KPCM
CMSEL,S,_LINECM
CMDEL,_LINECM
CMSEL,S,_AREACM
CMDEL,_AREACM
CMSEL,S,_VOLUCM
CMDEL,_VOLUCM
CMDEL,_TARGET
CMDEL,_CONTACT
FINISH
/SOL
SOLVE
FINISH
/POST1
FINISH
/SOL
FINISH
/PREP7
RMODIF,3,10,1
RMODIF,4,10,1
KEYOPT,3,5,1
KEYOPT,5,5,1
FINISH
/SOL
FLST,2,2,5,ORDE,2
FITEM,2,1
FITEM,2,9
/GO
DA,P51X,ALL,0
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,30
SOLVE
FINISH
/POST1
FINISH
/PREP7
CWZDELE,3,1,''
FINISH
/SOL
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,50
SOLVE
FINISH
/POST1
FINISH
/SOL
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,100
SOLVE
FINISH
/POST1
FINISH
/PREP7
RMODIF,4,4,-0.1
FINISH
/SOL
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,100
SOLVE
FINISH
/POST1
FINISH
/SOL
NLGEOM,0
NROPT,AUTO, ,OFF
LUMPM,0
EQSLV, , ,0,
PRECISION,0
MSAVE,0
PIVCHECK,1
DSOPT,LOCAL,AUTO,
DSPROC,1,
SSTIF,ON
TOFFST,0,
ANTYPE,0
NLGEOM,1
NSUBST,50,1000,2
OUTRES,ERASE
OUTRES,ALL,-5
TIME,100
OUTRES,ERASE
OUTRES,ALL,-5
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,100
SOLVE
FINISH
/POST1
SET,LIST,999
SET,,, ,,, ,3
SET,LIST,999
SET,,, ,,, ,4
SET,FIRST
SET,,,,,,,2
SET,,,,,,,3
SET,,,,,,,4
SET,,,,,,,3
SET,,,,,,,2
SET,,,,,,,1
SET,,,,,,,2
SET,,,,,,,3
SET,,,,,,,4
FINISH
/PREP7
RMODIF,4,4,-0.2
RMODIF,4,6,-10
FINISH
/POST1
FINISH
/SOL
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,100
SOLVE
FINISH
/PREP7
RMODIF,4,4,-1
RMODIF,4,6,-5
FINISH
/SOL
NSUBST,500,1000,2
OUTRES,ERASE
OUTRES,ALL,ALL
SOLVE
FINISH
/PREP7
RMODIF,4,6,
KEYOPT,5,5,0
KEYOPT,5,9,1
FINISH
/SOL
NSUBST,500,10000,2
TIME,10
SOLVE
FINISH
/POST1
SET,LAST
SET,FIRST
SET,,,,,,,2
SET,,,,,,,3
SET,,,,,,,4
SET,,,,,,,5
SET,,,,,,,6
SET,,,,,,,7
SET,,,,,,,10
SET,,,,,,,11
SET,,,,,,,12
SET,,,,,,,13
SET,,,,,,,14
SET,,,,,,,15
SET,,,,,,,14
SET,,,,,,,15
SET,,,,,,,14
SET,,,,,,,13
SET,,,,,,,1
SET,,,,,,,2
SET,,,,,,,3
SET,,,,,,,4
SET,,,,,,,5
SET,,,,,,,6
SET,,,,,,,7
SET,,,,,,,8
SET,,,,,,,10
SET,,,,,,,13
SET,,,,,,,15
SET,,,,,,,14
SET,,,,,,,13
SET,,,,,,,12
SET,,,,,,,11
SET,,,,,,,10
SET,,,,,,,9
SET,,,,,,,8
SET,,,,,,,9
SET,,,,,,,8
SET,,,,,,,7
SET,,,,,,,4
SET,,,,,,,1
SET,,,,,,,7
SET,,,,,,,10
SET,,,,,,,14
SET,,,,,,,15
SET,,,,,,,14
FINISH
/PREP7
RMODIF,4,4,-5
RMODIF,4,5,
RMODIF,4,11,-1.0
FINISH
/SOL
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
SFA,P51X,1,PRES,60
SOLVE
FINISH
/POST1
SET,FIRST
SET,,,,,,,2
SET,,,,,,,7
SET,,,,,,,9
SET,,,,,,,12
SET,,,,,,,14
SET,,,,,,,15
FINISH
/PREP7
FINISH
/SOL
FLST,2,1,5,ORDE,1
FITEM,2,20
/GO
DA,P51X,UZ,-3.5
SOLVE
FINISH
/POST1
FINISH
/PREP7
TB,BISO,1,1,2,
TBTEMP,0
TBDATA,,355,0.5,,,,
FINISH
/SOL
FINISH
/PREP7
FINISH
/SOL
SOLVE
FINISH
/POST1

 

[capollo]

Nonlin would cause a problem to contact solutions when you model is very far away from the origin. Move the model so that it is centered about the origin.

 

[samuelecorsi]

sorry capollo, but my model is very closed to the origin, the distances between contact surfaces and the origin of axes is only 50 millimeters. so I think that I've to try in another way. Thanks so much for your reply. have a nice day.
samuele