Convergence issues when running Nonlinear Buckling in Stiffened Plate

Hello. I am studying biaxial elastoplastic buckling, and I am having convergence issues. I am receiving the following error:

*** ERROR *** CP = 57.703 TIME= 16:45:19
Solution not converged at time 11.1825 (load step 1 substep 1).
Run terminated.

*** WARNING *** CP = 57.703 TIME= 16:45:19
The unconverged solution (identified as time 4473 substep 999999) is
output for analysis debug purposes. Results should not be used for
any other purpose.

My case study is elastoplastic buckling of stiffened plates, in which I use Bilinear Isotropic Hardening.

I am using PyMAPDL 0.68.4 and ANSYS Mechanical APDL 2024R2 Student Version.

The generated APDL script is attached.

I tried to introduce CNVTOL as a way to reach convergence, but without success.

How can I modify the script above in order of it to work?

Since now I thank very much for any piece of advice.

script.txt

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Comments

Erik Kostson

This forum is for scripting questions. As this is a convergence related issue (seen from the error), so a general APDL modeling/solver issue question I suggest Ansys Innovation Space / https://forum.ansys.com/forums/forum/discuss-simulation/structures/

Just paste the mapdl script (not pymapdl) into a post in the above link, because if it does not run natively in mapdl it will not run in pymapdl , and secondly Ansys empl. are not allowed to download any files.

andreiflancanova

The script in the attached file is an APDL one. I think it's a script issue because it doesn't work properly. I am seeking for help to fix the script in order to be able to run it properly.

The APDL code is this:

Part 1:

! APDL log script generated using PyMAPDL (ansys.mapdl.core 0.68.4)
/TITLE,phi_0.10_L_2_T_2_k_5.00_SP_192
SAVE,,,,ALL
/PREP7,
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
/GO
ET,1,SHELL281,,,,,,,
MPTEMP,,,,,,,
MPTEMP,1,0,,,,,
MPDATA,EX,1,,210000.00,,,,,
MPDATA,PRXY,1,,0.300,,,,,
sect,1,shell
SECDATA,18.00,1,0,3,,,,,,,,
SECOFFSET,TOP,,,,,,
SECCONTROL,,,,,,,,,,,,,
sect,2,shell
SECDATA,12.00,1,0,3,,,,,,,,
SECOFFSET,MID,,,,,,
SECCONTROL,0,0,0,0,1,1,1,,,,,,
K,1,667.0,0,0
K,2,667.0,1000.00,0
K,3,667.0,1000.00,58.00
K,4,667.0,0,58.00
K,5,0,333.0,0
K,6,2000.00,333.0,0
K,7,2000.00,333.0,58.00
K,8,0,333.0,58.00
FLST,2,4,3,,
FITEM,2,1,,
FITEM,2,2,,
FITEM,2,3,,
FITEM,2,4,,
A,P51X,,,,,,,,,,,,,,,,,
ASEL,S,LOC,X,660.33,673.67,,
tmpvar = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,enrijecedor_transversal, AREA
AGEN,2,enrijecedor_transversal,,,667.0,,,,,
ASEL,ALL,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,transversais_pre_aptn, AREA
FLST,2,4,3,,
FITEM,2,5,,
FITEM,2,6,,
FITEM,2,7,,
FITEM,2,8,,
A,P51X,,,,,,,,,,,,,,,,,
ASEL,ALL,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,S,LOC,Y,329.67,336.33,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,enrijecedor_longitudinal, AREA
AGEN,2,enrijecedor_longitudinal,,,,333.0,,,,
CMSEL,S,transversais_pre_aptn,
ASEL,INVE,AREA,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,longitudinais_pre_aptn, AREA
RECTNG,0,2000.00,0,1000.00
CMSEL,S,transversais_pre_aptn,
CMSEL,A,longitudinais_pre_aptn,
ASEL,INVE,AREA,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,placa_pre_aptn, AREA
ALLSEL,ALL,AREA
APTN,ALL,,,,,,,,
ASEL,ALL,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,S,LOC,X,266.8,400.2,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,A,LOC,X,933.8,1067.2,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,A,LOC,X,1600.8,1734.2,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,R,LOC,Z,-9.0,9.0,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,placa_pos_aptn, AREA
ASEL,ALL,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,S,LOC,X,266.8,400.2,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,A,LOC,X,933.8,1067.2,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,A,LOC,X,1600.8,1734.2,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,R,LOC,Z,23.2,34.8,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,longitudinais_pos_aptn, AREA
ASEL,ALL,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,S,LOC,Y,133.20000000000002,199.8,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,A,LOC,Y,466.2,506.16,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,A,LOC,Y,799.2,839.16,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
ASEL,R,LOC,Z,23.2,34.8,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
CM,transversais_pos_aptn, AREA
CMSEL,ALL,,
NUMMRG,ALL,,,,LOW
CMSEL,ALL,,
MSHAPE,0,2D
MSHKEY,0
TYPE,1
MAT,1
REAL
ESYS,0
SECNUM,1
AESIZE,placa_pos_aptn,20.0
AMESH,placa_pos_aptn,,
TYPE,1
MAT,1
REAL
ESYS,0
SECNUM,2
AESIZE,transversais_pos_aptn,20.0
AMESH,transversais_pos_aptn,,
TYPE,1
MAT,1
REAL
ESYS,0
SECNUM,2
AESIZE,longitudinais_pos_aptn,20.0
AMESH,longitudinais_pos_aptn,,
_tmpvar_ = wrinqr(1)
*GET,NELEM,ELEM,,count,,,,,,,
FINISH,
/SOLU,
ANTYPE,0
PSTRES,1
CMSEL,ALL,,
CMSEL,S,placa_pos_aptn,
LSLA,S
KSLL,S
KSEL,S,LOC,X,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,KP,,COUNT,,,,,,,
KSEL,R,LOC,Y,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,KP,,COUNT,,,,,,,
CM,kp_inferior_esquerdo, KP
DK,kp_inferior_esquerdo,UX,UY,0,0,,,,,
CMSEL,ALL,,
CMSEL,S,placa_pos_aptn,
LSLA,S
KSLL,S
KSEL,S,LOC,X,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,KP,,COUNT,,,,,,,
KSEL,R,LOC,Y,1000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,KP,,COUNT,,,,,,,
CM,kp_superior_esquerdo, KP
DK,kp_superior_esquerdo,UX,0,,,,,,,
CMSEL,ALL,,
CMSEL,S,placa_pos_aptn,
LSLA,S
KSLL,S
KSEL,S,LOC,X,2000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,KP,,COUNT,,,,,,,
KSEL,R,LOC,Y,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,KP,,COUNT,,,,,,,
CM,kp_inferior_direito, KP
DK,kp_inferior_direito,UY,0,,,,,,,
CMSEL,ALL,,
CMSEL,S,placa_pos_aptn,
LSLA,S
LSEL,S,LOC,X,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
LSEL,A,LOC,X,2000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
LSEL,A,LOC,Y,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
LSEL,A,LOC,Y,1000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
LSEL,R,LOC,Z,0,18.00,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_contorno_placa, LINE
CMSEL,ALL,,
CMSEL,S,lines_contorno_placa,
LSEL,R,LOC,X,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_contorno_placa_esquerda, LINE
CMSEL,ALL,,
CMSEL,S,lines_contorno_placa,
LSEL,R,LOC,X,2000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_contorno_placa_direita, LINE
CMGRP,lines_contorno_placa_ts,lines_contorno_placa_esquerda,lines_contorno_placa_direita,,,,,,
CMSEL,ALL,,
CMSEL,S,lines_contorno_placa,
LSEL,R,LOC,Y,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_contorno_placa_inferior, LINE
CMSEL,ALL,,
CMSEL,S,lines_contorno_placa,
LSEL,R,LOC,Y,1000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_contorno_placa_superior, LINE
CMGRP,lines_contorno_placa_ls,lines_contorno_placa_inferior,lines_contorno_placa_superior,,,,,,
CMSEL,ALL,,
DL,lines_contorno_placa,,UZ,0,
CMSEL,ALL,,
CMSEL,S,transversais_pos_aptn,
LSLA,S
LSEL,R,LOC,Y,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_borda_ts_inferior, LINE
CMSEL,ALL,,
CMSEL,S,transversais_pos_aptn,
LSLA,S
LSEL,R,LOC,Y,1000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_borda_ts_superior, LINE
CMGRP,lines_borda_ts,lines_borda_ts_inferior,lines_borda_ts_superior,,,,,,
CMSEL,ALL,,
CMSEL,S,longitudinais_pos_aptn,
LSLA,S
LSEL,R,LOC,X,0,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_borda_ls_esquerda, LINE
CMSEL,ALL,,
CMSEL,S,longitudinais_pos_aptn,
LSLA,S
LSEL,R,LOC,X,2000.00,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,LINE,,COUNT,,,,,,,
CM,lines_borda_ls_direita, LINE
CMGRP,lines_borda_ls,lines_borda_ls_esquerda,lines_borda_ls_direita,,,,,,
CMGRP,lines_borda_enrijecedores,lines_borda_ts,lines_borda_ls,,,,,,
CMSEL,ALL,,
DL,lines_borda_enrijecedores,,UZ,0,
FINISH,
SAVE,,,,ALL

andreiflancanova

Part 2:

! APDL log script generated using PyMAPDL (ansys.mapdl.core 0.68.4)
/CWD,'C:/constructal_automate_analysis_files/phi_0.10_L_2_T_2_k_5.00_SP_192'
RESUME,C:/constructal_automate_analysis_files/phi_0.10_L_2_T_2_k_5.00_SP_192/phi_0.10_L_2_T_2_k_5.00_SP_192.db,,,,
/SOLU,
ASEL,ALL,,,,,,
tmpvar = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
SFL,lines_contorno_placa_ts,PRESS,1.000,,,
SFL,lines_contorno_placa_ls,PRESS,1.000000,,,
SFL,lines_borda_ls,PRESS,1.000,,,
SFL,lines_borda_ts,PRESS,1.000000,,,
ASEL,ALL,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
SOLVE,
FINISH,
/SOLU
ANTYPE,1
BUCOPT,LANB,1,0,0,CENTER
MXPAND,1,0,0,0,0.001,,
SOLVE,
FINISH,
SAVE,,,,
/POST1
SAVE,,,,
NSEL,S,NODE,,NODE(1000.0,500.0,0)
PRNSOL,U,Z
FINISH,
! APDL log script generated using PyMAPDL (ansys.mapdl.core 0.68.4)
/CWD,'C:/constructal_automate_analysis_files/phi_0.10_L_2_T_2_k_5.00_SP_192'
RESUME,C:/constructal_automate_analysis_files/phi_0.10_L_2_T_2_k_5.00_SP_192/phi_0.10_L_2_T_2_k_5.00_SP_192.db,,,,
/SOLU,
ASEL,ALL,,,,,,
_tmpvar_ = wrinqr(1)
*GET,_floatparameter_,AREA,,COUNT,,,,,,,
/PREP7,
UPGEOM,0.50,LAST,LAST,C:/constructal_automate_analysis_files/phi_0.10_L_2_T_2_k_5.00_SP_192/phi_0.10_L_2_T_2_k_5.00_SP_192,
TB,BISO,1,1,2,,,
TBTEMP,0,
TBDATA,,355.00,0.00,,,,
/SOL
ANTYPE,0
NLGEOM,ON
NSUBST,200,400,100,
CNVTOL,F,0.1,,,
CNVTOL,U,0.1,,,
PSTRES,1
TIME,4473
SFL,lines_contorno_placa_ts,PRESS,4473,,,
SFL,lines_contorno_placa_ls,PRESS,4473,,,
SFL,lines_borda_ls,PRESS,4473,,,
SFL,lines_borda_ts,PRESS,4473,,,
SOLVE,

Pernelle Marone-Hitz

As my colleague mentioned, the issue you are having is related to the model not converging. This cannot be addressed in this forum. Here we only answer specific questions on scripting (not general questions and not debugging entire scripts). There are several tools to help debug a model that is not converging. Our peers in the other forum will be able to provide recommendations into resolving a non-convergence issue (and not make your model converge either).

andreiflancanova

Thank you for the directions, @Erik Kostson and @Pernelle Marone-Hitz

Sorry for posting in the wrong place