Convergence Problem 1

[DSB123]

Hi There Experts,
New to Ansys. Trying to get a contact problem to solve but it keeps kicking out after a time with no solution. Using Conta170 and Targe174 elements. Any ideas of what I need to do to get convergence?

Regards

 

[nick6831]

Hello everybody,
I am doing a non linear analysis of a I- sec steel column 3 m length considering the imperfections.
For imperfections i required a max. deflection of 12 mm at the centre...so i adjusted my load which gives me 12 mm def. at centre...then i used "upgeom" command to simulate the deflected shape in my non linear analysis file of the column....but i am facing the problem"solution is not converging at load step 1"

----file where i created imperfections----
/batch
finish
/clear,start


/PREP7
ET,1,SOLID45
KEYOPT,1,1,0
KEYOPT,1,2,1
KEYOPT,1,4,0 !defining the element solid45
KEYOPT,1,5,0
KEYOPT,1,6,0
R,1, ,
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,1,,210000 !material properties
MPDATA,PRXY,1,,.3
*SET,x1,0
*SET,y1,0
*SET,x2,144.5
*SET,y2,0
*SET,x3,165.5
*SET,y3,0
*SET,x4,310
*SET,y4,0
*SET,x5,310
*SET,y5,39
*SET,x6,165.5
*SET,y6,39
*SET,x7,144.5
*SET,y7,39
*SET,x8,0
*SET,y8,39 !defining the scalar parameters
*SET,x9,0
*SET,y9,301
*SET,x10,144.5
*SET,y10,301
*SET,x11,165.5
*SET,y11,301
*SET,x12,310
*SET,y12,301
*SET,x13,310
*SET,y13,340
*SET,x14,165.5
*SET,y14,340
*SET,x15,145.5
*SET,y15,340
*SET,x16,0
*SET,y16,340
K,1,x1,y1,,
K,2,x2,y2,,
K,3,x3,y3,,
K,4,x4,y4,,
K,5,x5,y5,,
K,6,x6,y6,,
K,7,x7,y7,,
K,8,x8,y8,,
K,9,x9,y9,,
K,10,x10,y10,,
K,11,x11,y11,, !plotting the keypoints
K,12,x12,y12,,
K,13,x13,y13,,
K,14,x14,y14,,
K,15,x15,y15,,
K,16,x16,y16,,
a,1,2,7,8
a,2,3,6,7
a,3,4,5,6
a,7,6,11,10
a,9,10,15,16
a,10,11,14,15
a,11,12,13,14
aglue,all
lesize,2,,,2
lesize,4,,,2
lesize,5,,,2
lesize,6,,,2
lesize,7,,,2
lesize,9,,,2
lesize,12,,,2
lesize,15,,,2
lesize,17,,,2
lesize,18,,,2
lesize,19,,,2
lesize,21,,,2
lesize,11,,,16 !giving the NDIV on lines
lesize,13,,,16
lesize,14,,,5
lesize,16,,,5
lesize,20,,,5
lesize,22,,,5
lesize,1,,,5
lesize,3,,,5
lesize,8,,,5
lesize,10,,,5
vext,all,,,0,0,-3000 !extruding the area


lesize,39,,,25
lesize,40,,,25
lesize,59,,,25
lesize,60,,,25
lesize,50,,,25
lesize,52,,,25
lesize,27,,,25
lesize,30,,,25
vmesh,all

!et,3,shell181
!type,3
!MPDATA,EX,3,,210000 !material properties
!MPDATA,PRXY,3,,.3
!r,3,1000
!real,3

!asel,s,loc,z,0
!asel,a,loc,z,-3000
!amesh,all
finish

/solu
nsel,s,loc,z,0
nsel,r,loc,x,155
d,all,uy
d,all,ux

nsel,s,loc,z,0 !hinge at the bottom
nsel,r,loc,x,155
nsel,r,loc,y,340/2
d,all,ux
d,all,uz

nsel,s,loc,z,-3000
nsel,r,loc,x,155
d,all,ux

nsel,s,loc,z,-3000
nsel,r,loc,x,155 !roller at the top
nsel,r,loc,y,340/2
d,all,uy
alls

local,111,0,155,170
nsel,s,loc,x,0
nsel,r,loc,y,0
*get,cnode,node,,count
*SET,load,1250000/cnode
f,all,fx,load
alls

solve
finish





---------non linear analysis file of I sec steel column-----
batch
finish
/clear,start


/PREP7
ET,1,SOLID45
KEYOPT,1,1,0
KEYOPT,1,2,1
KEYOPT,1,4,0 !defining the element solid45
KEYOPT,1,5,0
KEYOPT,1,6,0
R,1, ,
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,EX,1,1,200000
!MPDATA,EX,1,1,200000,204301.075,207142.857,205263.158,208333.333,207692.308,155555.556 !material properties
MPDATA,PRXY,1,,.3

TB,MISO,1,1,7
!TBTEMP,0
TBPT,,.00045,90
TBPT,,.00095,190
TBPT,,.00145,290
TBPT,,.00195,390
TBPT,,.0025,500
TBPT,,.0027,540
TBPT,,.0036,560


*SET,x1,0
*SET,y1,0
*SET,x2,144.5
*SET,y2,0
*SET,x3,165.5
*SET,y3,0
*SET,x4,310
*SET,y4,0
*SET,x5,310
*SET,y5,39
*SET,x6,165.5
*SET,y6,39
*SET,x7,144.5
*SET,y7,39
*SET,x8,0
*SET,y8,39 !defining the scalar parameters
*SET,x9,0
*SET,y9,301
*SET,x10,144.5
*SET,y10,301
*SET,x11,165.5
*SET,y11,301
*SET,x12,310
*SET,y12,301
*SET,x13,310
*SET,y13,340
*SET,x14,165.5
*SET,y14,340
*SET,x15,145.5
*SET,y15,340
*SET,x16,0
*SET,y16,340
K,1,x1,y1,,
K,2,x2,y2,,
K,3,x3,y3,,
K,4,x4,y4,,
K,5,x5,y5,,
K,6,x6,y6,,
K,7,x7,y7,,
K,8,x8,y8,,
K,9,x9,y9,,
K,10,x10,y10,,
K,11,x11,y11,, !plotting the keypoints
K,12,x12,y12,,
K,13,x13,y13,,
K,14,x14,y14,,
K,15,x15,y15,,
K,16,x16,y16,,
a,1,2,7,8
a,2,3,6,7
a,3,4,5,6
a,7,6,11,10
a,9,10,15,16
a,10,11,14,15
a,11,12,13,14
aglue,all
lesize,2,,,2
lesize,4,,,2
lesize,5,,,2
lesize,6,,,2
lesize,7,,,2
lesize,9,,,2
lesize,12,,,2
lesize,15,,,2
lesize,17,,,2
lesize,18,,,2
lesize,19,,,2
lesize,21,,,2
lesize,11,,,16 !giving the NDIV on lines
lesize,13,,,16
lesize,14,,,5
lesize,16,,,5
lesize,20,,,5
lesize,22,,,5
lesize,1,,,5
lesize,3,,,5
lesize,8,,,5
lesize,10,,,5
vext,all,,,0,0,-3000 !extruding the area


lesize,39,,,25
lesize,40,,,25
lesize,59,,,25
lesize,60,,,25
lesize,50,,,25
lesize,52,,,25
lesize,27,,,25
lesize,30,,,25
vmesh,all

et,3,shell181
type,3
MPDATA,EX,3,,210000 !material properties
MPDATA,PRXY,3,,.3
r,3,1000
real,3

asel,s,loc,z,0
asel,a,loc,z,-3000
amesh,all
allsel

!--------------imposing the imperfection on the column---------------------------
!UPGEOM,1,1,1,trial-1,rst
UPGEOM,1,1,1,trial.shell,rst

!--------------- from the previous file------------------------------------------

finish

/solu

ANTYPE,STATIC
NLGEOM,ON
OUTRES,ALL,ALL
!activating non linear buckling analysis options
NSUBST,500,1000,50
!NEQIT,5000
AUTOTS,ON
LNSRCH,ON

asel,s,loc,z,0
da,all,ux
da,all,uy
da,all,uz !Fixed support at the bottom
da,all,rotx
da,all,roty
da,all,rotz

nsel,s,loc,z,-3000
nsel,r,loc,x,155
d,all,ux

nsel,s,loc,z,-3000
nsel,r,loc,x,155 !Roller at the top
nsel,r,loc,y,340/2
d,all,uy
alls

!nsel,s,loc,z,-3000
!nsel,r,loc,x,19.5
!d,all,ux
!d,all,uy

!nsel,s,loc,z,-3000
!nsel,r,loc,x,320.5
!d,all,ux
!d,all,uy

nsel,s,loc,z,-3000
nsel,r,loc,x,155
nsel,r,loc,y,340/2 !point load at the top central node 80 MN
f,all,fz,.080e9

allsel
solve
finish

 

[aminjamali]

I would be a lil bit more detailed, but anyway, most of times some friction helps, define 0.1 (or even 0.2) as the coefficient of friction, see if it helps.

 

[nick6831]

hi aminjamali
i will try with your suggestion.
thanx

 

[DSB123]

Nick6831,
It's not the normal thing to do in these forums - highjacking an existing thread.You should start a new thread!! However in this case since I did not get nay replies then there's no harm done!!

 

[aminjamali]

my answer was referring to DSB123's problem.

cheers