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.

Comments

  • Erik Kostson
    Erik Kostson Member, Employee Posts: 209
    50 Answers 100 Comments Photogenic 5 Likes
    ✭✭✭✭
    edited September 24

    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
    andreiflancanova Member Posts: 4
    First Comment Name Dropper
    **

    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
    andreiflancanova Member Posts: 4
    First Comment Name Dropper
    **

    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
    Pernelle Marone-Hitz Member, Moderator, Employee Posts: 871
    500 Comments Photogenic Name Dropper Solution Developer Community of Practice Member
    ✭✭✭✭

    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
    andreiflancanova Member Posts: 4
    First Comment Name Dropper
    **

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

    Sorry for posting in the wrong place