non-linear analysis problems in ANSYS

[gjaver]

Hi all,

I'm currently having some troubles analysing a beam (BEAM189)structure in ANSYS APDL 13.0. The problem is that I want to define some imperfections in the beam grid by adding displacements with the UPGEOM command, calculated in a earlier calculation.

After addition of the displacements, I try to solve and the analysis terminates with the following error:

*** ERROR *** CP = 2046.641 TIME= 11:48:29
Element @@@ integration 1 point is located outside of end stations.
Please verify section input 1.000007321.

When I minimize the imperfections to 1e-6 mm, the error does not occur. In my opinion, with this small imperfections I could neglect is at all.

Part of the code is added below

Could anyone push me in the right direction?

Thanks in advance

##################################################

/SOLU
ANTYPE,STATIC
PSTRESS,ON
SOLVE
FINI

/SOLU
OUTRESS,ALL,ALL
ANTYPE,BUCKLE
BUCOPT,LANB,10
SOLVE
FINISH

/PREP7
CSYS,0
ALS
*DO,i,1,6
UPGEOM,1,1,i,file,rst
*ENDDO
ALS
FINI

/SOLU
ANTYPE,STATIC
OUTRES,ALL,ALL
OUTRES,LOCI
NLGEOM,ON
PSTRES,ON
SOLVE
FINI

 

[flash3780]

Not sure about the error, but the UPGEOM command is cumulative. So, you're summing the displacements from load steps 1-6. Is that what you want to do?

Also, I think OUTRES only has one "S" (line 8).

 

[gjaver]

Thanks for your reply.

True, I'm summing the displacements of the first 6 buckling shapes. It does not matter if I take 1 or 6.

I coorected the typo. This has no effect.

It looks that the UPGEOM command changes the end coordinates of the element but the integration points in the usermeshed section does not shift together with this coordinate change.