Buckling and post-buckling analysis of a ring-stiffened cylinder using nonlinear stabilization#

This examples shows how to use PyMAPDL to import an existing FE model and to perform a7 nonlinear buckling and post-buckling analysis using nonlinear stabilization. The problem uses a stiffened cylinder subjected to uniform external pressure to show how to find the nonlinear buckling loads, achieve convergence at the post-buckling stage, and interpret the results.

This example is inspired from the model and analysis defined in Chapter 21 of the Mechanical APDL Technology Showcase Manual.

Setting up model#

The original FE model is given in the Ansys Mechanical APDL Technology Showcase Manual. The .cdb contains a FE model of a ring-stiffened cylinder.

A circular cylinder made of bare 2024-T3 aluminum alloy is stiffened inside with five Z-section rings. Its ends are closed with thick aluminum bulkheads. A riveted L section exists between the top plate and the top ring and the bottom plate and bottom ring. The cylinder is subjected to a differential external pressure. The pressure causes a local buckling phenomenon characterized by buckling of the skin between stiffening rings, leading eventually to collapse.

The finite element model of the ring stiffened cylinder is meshed with SHELL281 elements with an element size of 10 mm. The fine mesh is required for buckling analysis, and a full 360-degree model is necessary because the deformation is no longer axisymmetric after buckling occurs.

All shell elements have uniform thickness. Five sections are created in the model with no offsets, so the shell sections are offset to the midplane by default.

Starting MAPDL as a service and importing an external model#

from ansys.mapdl.core import launch_mapdl
from ansys.mapdl.core.examples.downloads import download_tech_demo_data

# define geometric parameters
bs = 95.3  # Ring spacing (mm)
ts = 1.034  # Skin thickness (mm)
tw = 0.843  # Ring thickness (mm)
r = 344 * ts  # Radius of cylinder (mm)
L = 431.8 + 2 * (19 - 9.5)  # Length of cylinder (mm)
pext = 0.24  # Differential external pressure (MPa)

# start MAPDL as a service
mapdl = launch_mapdl()
print(mapdl)

mapdl.filname("buckling")  # change filename
# mapdl.nerr(nmerr=200, nmabt=10000, abort=-1, ifkey=0, num=0)

# enter preprocessor
mapdl.prep7()

# define material properties for 2024-T3 Alluminum alloy
EX = 73000  # Young's Modulus (MPA)
ET = 73  # Tangent modulus
mapdl.mp("ex", 1, EX)  # Young's Modulus (MPA)
mapdl.mp("prxy", 1, 0.33)  # Poisson's ratio
EP = EX * ET / (EX - ET)
mapdl.tb("biso", 1)
mapdl.tbdata(1, 268.9, EP)
# create material plot
mapdl.show("png")
mapdl.tbplot("biso", 1)
mapdl.show("close")

# define shell elements and their sections
mapdl.et(1, 181)
# cylinder
mapdl.sectype(1, "shell")
mapdl.secdata(ts, 1)
# L
mapdl.sectype(2, "shell")
mapdl.secdata(ts + 1.64, 1)
# Z shaped ring stiffener
mapdl.sectype(3, "shell")
mapdl.secdata(tw, 1)
# Plate at z=0 with thickness=25 mm
mapdl.sectype(4, "shell")
mapdl.secdata(25, 1)
# Plate at z=L  with thickness=25 mm
mapdl.sectype(5, "shell")
mapdl.secdata(25, 1)


# read model of stiffened cylinder
# download the cdb file
ring_mesh_file = download_tech_demo_data(
    "td-21", "ring_stiffened_cylinder_mesh_file.cdb"
)

# read in cdb
mapdl.cdread("db", ring_mesh_file)
mapdl.allsel()
mapdl.eplot(background="w")
mapdl.cmsel("all")
21 example technology showcase buckling21 example technology showcase buckling
Product:             Ansys Mechanical Enterprise
MAPDL Version:       23.1
ansys.mapdl Version: 0.65.dev0


ALSO SELECT ALL COMPONENTS

Define static prestress analysis#

Displacement boundary conditions are defined to prevent the six rigid body motions. A total of six displacements are therefore applied to three nodes located on the top plate at 0, 90, and 270 degrees; the nodes are restricted so that all rigid translations and rotations are not possible for the cylinder.

Loading consists of a uniformly distributed external differential pressure: \(P_{ext} = 0.24 MPa\)

print("Begin static prestress analysis")

mapdl.csys(1)  # activate cylindrical coordinate system

# Define pressure on plate at z=0
mapdl.nsel("s", "loc", "z", 0)
mapdl.esln("s", 1)
mapdl.sfe("all", 2, "pres", 1, pext)
mapdl.allsel()

# Define pressure on the rim of plate at z=0
mapdl.nsel("s", "loc", "z", 0)
mapdl.nsel("r", "loc", "x", r - ts / 2, 760 / 2)
mapdl.esln("s", 1)
mapdl.sfe("all", 1, "pres", 1, pext)
mapdl.allsel()

# Define pressure on plate at z=L
mapdl.nsel("s", "loc", "z", L)
mapdl.esln("s", 1)
mapdl.sfe("all", 2, "pres", 1, pext)
mapdl.allsel()

# Define pressure on the rim of plate at z=L
mapdl.nsel("s", "loc", "z", L)
mapdl.nsel("r", "loc", "x", r - ts / 2, 760 / 2)
mapdl.esln("s", 1)
mapdl.sfe("all", 1, "pres", 1, pext)
mapdl.allsel()

# Define pressure on cylinder
mapdl.nsel("s", "loc", "x", r - ts / 2)
mapdl.esln("s", 1)
mapdl.sfe("all", 2, "pres", 1, pext)
mapdl.allsel()

# Define displacement BSs to avoid rigid body motion
mapdl.csys(0)  # activate cartesian coordinate system
mapdl.nsel("s", "loc", "x", r - ts / 2)
mapdl.nsel("r", "loc", "y", 0)
mapdl.nsel("r", "loc", "z", 0)
mapdl.d("all", "ux", 0)
mapdl.d("all", "uy", 0)
mapdl.d("all", "uz", 0)
mapdl.allsel()
#
mapdl.nsel("s", "loc", "x", 0)
mapdl.nsel("r", "loc", "y", r - ts / 2)
mapdl.nsel("r", "loc", "z", 0)
mapdl.d("all", "uz", 0)
mapdl.allsel()
#
mapdl.nsel("s", "loc", "x", 0)
mapdl.nsel("r", "loc", "y", -(r - ts / 2))
mapdl.nsel("r", "loc", "z", 0)
mapdl.d("all", "uy", 0)
mapdl.d("all", "uz", 0)
mapdl.allsel()
#

# Print DOF constraints
print(mapdl.dlist())

# Solve static prestress analysis
mapdl.slashsolu()
mapdl.pstres("on")
mapdl.antype("STATIC")
output = mapdl.solve()
print(output)

# Plot total deformation
mapdl.post1()
mapdl.set("last")
mapdl.post_processing.plot_nodal_displacement("NORM", smooth_shading=True)

print("End static prestress analysis")
21 example technology showcase buckling
Begin static prestress analysis
LIST CONSTRAINTS FOR SELECTED NODES         1 TO    85474 BY        1
 CURRENTLY SELECTED DOF SET= UX   UY   UZ   ROTX ROTY ROTZ
   *****MAPDL VERIFICATION RUN ONLY*****
     DO NOT USE RESULTS FOR PRODUCTION

     NODE  LABEL     REAL           IMAG
         1  UX     0.00000000      0.00000000
         1  UY     0.00000000      0.00000000
         1  UZ     0.00000000      0.00000000
         2  UZ     0.00000000      0.00000000
       902  UY     0.00000000      0.00000000
       902  UZ     0.00000000      0.00000000
*****  MAPDL SOLVE    COMMAND  *****

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 There is no title defined for this analysis.

 *** WARNING ***                         CP =       0.000   TIME= 00:00:00
 Section ID set 2 (and possibly others), with only 1 layer and 3
 integration points, is associated with material plasticity.  The
 number of integration points will be changed to 5 for improved
 accuracy.

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 The model data was checked and warning messages were found.
  Please review output or errors file ( ) for these warning messages.

 *** SELECTION OF ELEMENT TECHNOLOGIES FOR APPLICABLE ELEMENTS ***
                ---GIVE SUGGESTIONS ONLY---

 ELEMENT TYPE         1 IS SHELL281. IT IS ASSOCIATED WITH ELASTOPLASTIC
 MATERIALS ONLY. KEYOPT(8)=2 IS SUGGESTED.


   *****MAPDL VERIFICATION RUN ONLY*****
     DO NOT USE RESULTS FOR PRODUCTION

                       S O L U T I O N   O P T I O N S

   PROBLEM DIMENSIONALITY. . . . . . . . . . . . .3-D
   DEGREES OF FREEDOM. . . . . . UX   UY   UZ   ROTX ROTY ROTZ
   ANALYSIS TYPE . . . . . . . . . . . . . . . . .STATIC (STEADY-STATE)
   PRESTRESS EFFECTS CALCULATED. . . . . . . . . .YES
   PLASTIC MATERIAL PROPERTIES INCLUDED. . . . . .YES
   NEWTON-RAPHSON OPTION . . . . . . . . . . . . .PROGRAM CHOSEN
   GLOBALLY ASSEMBLED MATRIX . . . . . . . . . . .SYMMETRIC

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 Present time 0 is less than or equal to the previous time.  Time will
 default to 1.

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 This nonlinear analysis defaults to using the full Newton-Raphson
 solution procedure.  This can be modified using the NROPT command.

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 The conditions for direct assembly have been met.  No .emat or .erot
 files will be produced.

 *** WARNING ***                         CP =       0.000   TIME= 00:00:00
 The program chosen initial timestep/load-factor is arbitrary.  It is
 necessary for the user to supply a suitable initial
 timestep/load-factor through the NSUB or DELTIM command for
 convergence and overall efficiency.



     D I S T R I B U T E D   D O M A I N   D E C O M P O S E R

  ...Number of elements: 26796
  ...Number of nodes:    73662
  ...Decompose to 0 CPU domains
  ...Element load balance ratio =     0.000


                      L O A D   S T E P   O P T I O N S

   LOAD STEP NUMBER. . . . . . . . . . . . . . . .     1
   TIME AT END OF THE LOAD STEP. . . . . . . . . .  1.0000
   AUTOMATIC TIME STEPPING . . . . . . . . . . . .    ON
      INITIAL NUMBER OF SUBSTEPS . . . . . . . . .     1
      MAXIMUM NUMBER OF SUBSTEPS . . . . . . . . .  1000
      MINIMUM NUMBER OF SUBSTEPS . . . . . . . . .     1
      START WITH TIME STEP FROM PREVIOUS SUBSTEP .   YES
   MAXIMUM NUMBER OF EQUILIBRIUM ITERATIONS. . . .    15
   STEP CHANGE BOUNDARY CONDITIONS . . . . . . . .    NO
   TERMINATE ANALYSIS IF NOT CONVERGED . . . . . .YES (EXIT)
   CONVERGENCE CONTROLS. . . . . . . . . . . . . .USE DEFAULTS
   COPY INTEGRATION POINT VALUES TO NODE . . . . .YES, FOR ELEMENTS WITH
                                                  ACTIVE MAT. NONLINEARITIES
   PRINT OUTPUT CONTROLS . . . . . . . . . . . . .NO PRINTOUT
   DATABASE OUTPUT CONTROLS. . . . . . . . . . . .ALL DATA WRITTEN
                                                  FOR THE LAST SUBSTEP


 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 Predictor is ON by default for structural elements with rotational
 degrees of freedom.  Use the PRED,OFF command to turn the predictor
 OFF if it adversely affects the convergence.


 Range of element maximum matrix coefficients in global coordinates
 Maximum = 489978589 at element 0.
 Minimum = 165335.668 at element 0.

   *** ELEMENT MATRIX FORMULATION TIMES
     TYPE    NUMBER   ENAME      TOTAL CP  AVE CP

        1     26796  SHELL281      0.000   0.000000
 Time at end of element matrix formulation CP = 0.

 ALL CURRENT MAPDL DATA WRITTEN TO FILE NAME=
  FOR POSSIBLE RESUME FROM THIS POINT
     FORCE CONVERGENCE VALUE  =   3478.      CRITERION=   17.39
     MOMENT CONVERGENCE VALUE =   0.000      CRITERION=   15.96

 DISTRIBUTED SPARSE MATRIX DIRECT SOLVER.
  Number of equations =      441966,    Maximum wavefront =      0
  Memory available (MB) =    0.0    ,  Memory required (MB) =    0.0

 Distributed sparse solver maximum pivot= 0 at node 0 .
 Distributed sparse solver minimum pivot= 0 at node 0 .
 Distributed sparse solver minimum pivot in absolute value= 0 at node 0
 .
     DISP CONVERGENCE VALUE   =   2.213      CRITERION=  0.1106
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  -2.213
     FORCE CONVERGENCE VALUE  =  0.5808E-05  CRITERION=   17.39     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.2147E-05  CRITERION=   15.96     <<< CONVERGED

 *** WARNING ***                         CP =       0.000   TIME= 00:00:00
 A reference moment value times the tolerance is used by the
 Newton-Raphson method for checking convergence.  The calculated
 reference MOMENT CONVERGENCE VALUE = 0 is less than a threshold.  This
 threshold is internally calculated.  You can overwrite it by
 specifying MINREF on the CNVTOL command.  Check results carefully.
     DISP CONVERGENCE VALUE   =  0.7695E-09  CRITERION=  0.1106     <<< CONVERGED
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC =  0.7695E-09
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   2

   *** ELEMENT RESULT CALCULATION TIMES
     TYPE    NUMBER   ENAME      TOTAL CP  AVE CP

        1     26796  SHELL281      0.000   0.000000

   *** NODAL LOAD CALCULATION TIMES
     TYPE    NUMBER   ENAME      TOTAL CP  AVE CP

        1     26796  SHELL281      0.000   0.000000
 *** LOAD STEP     1   SUBSTEP     1  COMPLETED.    CUM ITER =      2
 *** TIME =   1.00000         TIME INC =   1.00000
End static prestress analysis

Run linear buckling analysis#

This preliminary analysis predicts the theoretical buckling pressure of the ideal linear elastic structure (perfect cylinder) and the buckled mode shapes used in the next step to generate the imperfections. It is also an efficient way to check the completeness and correctness of modeling. To run the linear buckling analysis, a static solution with prestress effects must be obtained, followed by the eigenvalue buckling solution using the Block Lanczos method and mode expansion.

print("Begin linear buckling analysis")

# Define and solve linear buckling analysis
mapdl.slashsolu()
mapdl.outres("all", "all")
mapdl.antype("BUCKLE")
mapdl.bucopt("lanb", "10")
mapdl.mxpand(10)
output = mapdl.solve()
print(output)

# Plot total deformation of first and 10th mode
mapdl.post1()
mapdl.set(1, 1)
mapdl.post_processing.plot_nodal_displacement("NORM", smooth_shading=True)
mapdl.set(1, 10)
mapdl.post_processing.plot_nodal_displacement("NORM", smooth_shading=True)

print("End linear buckling analysis")
  • 21 example technology showcase buckling
  • 21 example technology showcase buckling
Begin linear buckling analysis
*****  MAPDL SOLVE    COMMAND  *****

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 There is no title defined for this analysis.

 *** SELECTION OF ELEMENT TECHNOLOGIES FOR APPLICABLE ELEMENTS ***
                ---GIVE SUGGESTIONS ONLY---

 ELEMENT TYPE         1 IS SHELL281. IT IS ASSOCIATED WITH ELASTOPLASTIC
 MATERIALS ONLY. KEYOPT(8)=2 IS SUGGESTED.


   *****MAPDL VERIFICATION RUN ONLY*****
     DO NOT USE RESULTS FOR PRODUCTION

                       S O L U T I O N   O P T I O N S

   PROBLEM DIMENSIONALITY. . . . . . . . . . . . .3-D
   DEGREES OF FREEDOM. . . . . . UX   UY   UZ   ROTX ROTY ROTZ
   ANALYSIS TYPE . . . . . . . . . . . . . . . . .BUCKLING
      EXTRACTION METHOD. . . . . . . . . . . . . .BLOCK LANCZOS
   PRESTRESS EFFECTS INCLUDED IF AVAILABLE . . . .YES
   GLOBALLY ASSEMBLED MATRIX . . . . . . . . . . .SYMMETRIC

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 The conditions for direct assembly have been met.  No .emat or .erot
 files will be produced.

                      L O A D   S T E P   O P T I O N S

   LOAD STEP NUMBER. . . . . . . . . . . . . . . .     1
   PRINT OUTPUT CONTROLS . . . . . . . . . . . . .NO PRINTOUT
   DATABASE OUTPUT CONTROLS
      ITEM     FREQUENCY   COMPONENT
       ALL        ALL


  BLOCK LANCZOS CALCULATION OF UP TO    10 EIGENVECTORS.
  NUMBER OF EQUATIONS              =       441966
  MAXIMUM WAVEFRONT                =            0
  MAXIMUM MODES STORED             =           10
  MINIMUM EIGENVALUE               = -0.10000E+31
  MAXIMUM EIGENVALUE               =  0.10000E+31
  CENTER EIGENVALUE                =  0.00000E+00

   *****MAPDL VERIFICATION RUN ONLY*****
     DO NOT USE RESULTS FOR PRODUCTION

  ***** EIGENVALUES (LOAD MULTIPLIERS FOR BUCKLING) *****
            *** FROM BLOCK LANCZOS ITERATION ***

      SHAPE NUMBER   LOAD MULTIPLIER

            1           0.62493510
            2           0.62493510
            3           0.62746216
            4           0.62748425
            5           0.63023610
            6           0.63025918
            7           0.63985985
            8           0.63985995
            9           0.64191573
           10           0.64191576
End linear buckling analysis

Generate imperfections#

If a structure is perfectly symmetric, nonsymmetric buckling does not occur numerically, and a nonlinear buckling analysis fails because nonsymmetric buckling responses cannot be triggered. In this problem, the geometry, elements, and pressure are all axisymmetric. It is not possible, therefore, to simulate nonaxisymmetric buckling with the initial model. To overcome this problem, small geometric imperfections (similar to those caused by manufacturing a real structure) must be introduced to trigger the buckling responses. Because the radius of the cylinder is 355.69 mm and the maximum displacement of a mode shape is 1 mm, a factor of 0.1 is applied when updating the geometry with mode shapes. The factor assumes the manufacturing tolerance of the radius to be on the order of 0.1.

print("Begin adding imperfections")

mapdl.finish()
mapdl.prep7()
for i in range(1, 11):
    mapdl.upgeom(0.1, 1, i, "buckling", "rst")  # Add imperfections as a tenth of each
    # mode shape
mapdl.finish()

print("Finish adding imperfections")
Begin adding imperfections
Finish adding imperfections

Run nonlinear static analysis on geometry with imperfections#

The nonlinear buckling analysis is a static analysis performed after adding imperfections with large deflection active (NLGEOM,ON), extended to a point where the stiffened cylinder can reach its limit load. To perform the analysis, the load must be allowed to increase using very small time increments so that the expected critical buckling load can be predicted accurately. Note - as this is a buckling analysis, divergence is expected.

print("Begin nonlinear static analysis on imperfect geometry")

mapdl.slashsolu()
mapdl.antype("STATIC")
mapdl.nlgeom("on")
mapdl.pred("on")
mapdl.time(1)
mapdl.nsubst(100, 10000, 10)
mapdl.rescontrol("define", "all", 1)
mapdl.outres("all", "all")
mapdl.ncnv(2)  # Do not terminate the program execution if the solution diverges
mapdl.allow_ignore = True  # in order for PyMAPDL to not raise an error
output = mapdl.solve()
print(output)
mapdl.finish()

print("End nonlinear static analysis on imperfect geometry")
Begin nonlinear static analysis on imperfect geometry
*****  MAPDL SOLVE    COMMAND  *****

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 There is no title defined for this analysis.

 *** SELECTION OF ELEMENT TECHNOLOGIES FOR APPLICABLE ELEMENTS ***
                ---GIVE SUGGESTIONS ONLY---

 ELEMENT TYPE         1 IS SHELL281. IT IS ASSOCIATED WITH ELASTOPLASTIC
 MATERIALS ONLY. KEYOPT(8)=2 IS SUGGESTED.


   *****MAPDL VERIFICATION RUN ONLY*****
     DO NOT USE RESULTS FOR PRODUCTION

                       S O L U T I O N   O P T I O N S

   PROBLEM DIMENSIONALITY. . . . . . . . . . . . .3-D
   DEGREES OF FREEDOM. . . . . . UX   UY   UZ   ROTX ROTY ROTZ
   ANALYSIS TYPE . . . . . . . . . . . . . . . . .STATIC (STEADY-STATE)
   NONLINEAR GEOMETRIC EFFECTS . . . . . . . . . .ON
   PLASTIC MATERIAL PROPERTIES INCLUDED. . . . . .YES
   NEWTON-RAPHSON OPTION . . . . . . . . . . . . .PROGRAM CHOSEN
   GLOBALLY ASSEMBLED MATRIX . . . . . . . . . . .SYMMETRIC

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 This nonlinear analysis defaults to using the full Newton-Raphson
 solution procedure.  This can be modified using the NROPT command.

 *** NOTE ***                            CP =       0.000   TIME= 00:00:00
 The conditions for direct assembly have been met.  No .emat or .erot
 files will be produced.



     D I S T R I B U T E D   D O M A I N   D E C O M P O S E R

  ...Number of elements: 26796
  ...Number of nodes:    73662
  ...Decompose to 0 CPU domains
  ...Element load balance ratio =     0.000


                      L O A D   S T E P   O P T I O N S

   LOAD STEP NUMBER. . . . . . . . . . . . . . . .     1
   TIME AT END OF THE LOAD STEP. . . . . . . . . .  1.0000
   AUTOMATIC TIME STEPPING . . . . . . . . . . . .    ON
      INITIAL NUMBER OF SUBSTEPS . . . . . . . . .   100
      MAXIMUM NUMBER OF SUBSTEPS . . . . . . . . . 10000
      MINIMUM NUMBER OF SUBSTEPS . . . . . . . . .    10
   MAXIMUM NUMBER OF EQUILIBRIUM ITERATIONS. . . .    15
   STEP CHANGE BOUNDARY CONDITIONS . . . . . . . .    NO
   STRESS-STIFFENING . . . . . . . . . . . . . . .    ON
   PREDICTOR USAGE . . . . . . . . . . . . . . . .ON (AFTER FIRST SUBSTEP)
   TERMINATE ANALYSIS IF NOT CONVERGED . . . . . .YES (REMAIN)
   CONVERGENCE CONTROLS. . . . . . . . . . . . . .USE DEFAULTS
   COPY INTEGRATION POINT VALUES TO NODE . . . . .YES, FOR ELEMENTS WITH
                                                  ACTIVE MAT. NONLINEARITIES
   PRINT OUTPUT CONTROLS . . . . . . . . . . . . .NO PRINTOUT
   DATABASE OUTPUT CONTROLS
      ITEM     FREQUENCY   COMPONENT
       ALL        ALL



 Range of element maximum matrix coefficients in global coordinates
 Maximum = 489978592 at element 0.
 Minimum = 165328.012 at element 0.

   *** ELEMENT MATRIX FORMULATION TIMES
     TYPE    NUMBER   ENAME      TOTAL CP  AVE CP

        1     26796  SHELL281      0.000   0.000000
 Time at end of element matrix formulation CP = 0.

 ALL CURRENT MAPDL DATA WRITTEN TO FILE NAME=
  FOR POSSIBLE RESUME FROM THIS POINT
     FORCE CONVERGENCE VALUE  =   34.78      CRITERION=  0.1739
     MOMENT CONVERGENCE VALUE =  0.1824E-05  CRITERION=  0.1596

 DISTRIBUTED SPARSE MATRIX DIRECT SOLVER.
  Number of equations =      441966,    Maximum wavefront =      0
  Memory available (MB) =    0.0    ,  Memory required (MB) =    0.0

 Distributed sparse solver maximum pivot= 0 at node 0 .
 Distributed sparse solver minimum pivot= 0 at node 0 .
 Distributed sparse solver minimum pivot in absolute value= 0 at node 0
 .
     DISP CONVERGENCE VALUE   =  0.2221E-01  CRITERION=  0.1110E-02
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2221E-01
     FORCE CONVERGENCE VALUE  =   1.654      CRITERION=  0.1739
     MOMENT CONVERGENCE VALUE =  0.2307      CRITERION=  0.1596
     DISP CONVERGENCE VALUE   =  0.2244E-03  CRITERION=  0.1111E-02 <<< CONVERGED
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2244E-03
     FORCE CONVERGENCE VALUE  =  0.2717E-03  CRITERION=  0.1739     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.1623E-03  CRITERION=  0.1596     <<< CONVERGED

 *** WARNING ***                         CP =       0.000   TIME= 00:00:00
 A reference moment value times the tolerance is used by the
 Newton-Raphson method for checking convergence.  The calculated
 reference MOMENT CONVERGENCE VALUE = 0 is less than a threshold.  This
 threshold is internally calculated.  You can overwrite it by
 specifying MINREF on the CNVTOL command.  Check results carefully.
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   2

   *** ELEMENT RESULT CALCULATION TIMES
     TYPE    NUMBER   ENAME      TOTAL CP  AVE CP

        1     26796  SHELL281      0.000   0.000000

   *** NODAL LOAD CALCULATION TIMES
     TYPE    NUMBER   ENAME      TOTAL CP  AVE CP

        1     26796  SHELL281      0.000   0.000000
 *** LOAD STEP     1   SUBSTEP     1  COMPLETED.    CUM ITER =      2
 *** TIME =  0.100000E-01     TIME INC =  0.100000E-01
 *** AUTO STEP TIME:  NEXT TIME INC = 0.10000E-01  UNCHANGED

     FORCE CONVERGENCE VALUE  =   3.342      CRITERION=  0.3478
     MOMENT CONVERGENCE VALUE =  0.4703      CRITERION=  0.3191
     DISP CONVERGENCE VALUE   =  0.4679E-03  CRITERION=  0.1111E-02 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.4679E-03
     FORCE CONVERGENCE VALUE  =  0.1163E-02  CRITERION=  0.3478     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.2879E-03  CRITERION=  0.3191     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   1
 *** LOAD STEP     1   SUBSTEP     2  COMPLETED.    CUM ITER =      3
 *** TIME =  0.200000E-01     TIME INC =  0.100000E-01
 *** AUTO TIME STEP:  NEXT TIME INC = 0.15000E-01  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =   6.409      CRITERION=  0.6086
     MOMENT CONVERGENCE VALUE =  0.9124      CRITERION=  0.5585
     DISP CONVERGENCE VALUE   =  0.9445E-03  CRITERION=  0.1667E-02 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.9445E-03
     FORCE CONVERGENCE VALUE  =  0.4674E-02  CRITERION=  0.6086     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.6922E-03  CRITERION=  0.5585     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   1
 *** LOAD STEP     1   SUBSTEP     3  COMPLETED.    CUM ITER =      4
 *** TIME =  0.350000E-01     TIME INC =  0.150000E-01
 *** AUTO TIME STEP:  NEXT TIME INC = 0.22500E-01  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =   14.89      CRITERION=  0.9998
     MOMENT CONVERGENCE VALUE =   2.142      CRITERION=  0.9175
     DISP CONVERGENCE VALUE   =  0.2356E-02  CRITERION=  0.2502E-02 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2356E-02
     FORCE CONVERGENCE VALUE  =  0.2851E-01  CRITERION=  0.9998     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.3006E-02  CRITERION=  0.9175     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   1
 *** LOAD STEP     1   SUBSTEP     4  COMPLETED.    CUM ITER =      5
 *** TIME =  0.575000E-01     TIME INC =  0.225000E-01
 *** AUTO TIME STEP:  NEXT TIME INC = 0.33750E-01  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =   35.48      CRITERION=   1.587
     MOMENT CONVERGENCE VALUE =   5.147      CRITERION=   1.456
     DISP CONVERGENCE VALUE   =  0.6229E-02  CRITERION=  0.3757E-02
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.6229E-02
     FORCE CONVERGENCE VALUE  =  0.1940      CRITERION=   1.587     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.1811E-01  CRITERION=   1.456     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2802E-04  CRITERION=  0.3757E-02 <<< CONVERGED
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC = -0.2802E-04
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   2
 *** LOAD STEP     1   SUBSTEP     5  COMPLETED.    CUM ITER =      7
 *** TIME =  0.912500E-01     TIME INC =  0.337500E-01
 *** AUTO TIME STEP:  NEXT TIME INC = 0.50625E-01  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =   88.92      CRITERION=   2.467
     MOMENT CONVERGENCE VALUE =   12.81      CRITERION=   2.264
     DISP CONVERGENCE VALUE   =  0.1802E-01  CRITERION=  0.5646E-02
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1802E-01
     FORCE CONVERGENCE VALUE  =   1.576      CRITERION=   2.467     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.1360      CRITERION=   2.264     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2509E-03  CRITERION=  0.5646E-02 <<< CONVERGED
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC = -0.2509E-03
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   2
 *** LOAD STEP     1   SUBSTEP     6  COMPLETED.    CUM ITER =      9
 *** TIME =  0.141875         TIME INC =  0.506250E-01
 *** AUTO TIME STEP:  NEXT TIME INC = 0.75938E-01  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =   252.2      CRITERION=   3.787
     MOMENT CONVERGENCE VALUE =   33.74      CRITERION=   3.475
     DISP CONVERGENCE VALUE   =  0.6000E-01  CRITERION=  0.1142E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.6000E-01
     FORCE CONVERGENCE VALUE  =   17.33      CRITERION=   3.787
     MOMENT CONVERGENCE VALUE =   1.320      CRITERION=   3.475     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2965E-02  CRITERION=  0.1157E-01 <<< CONVERGED
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2965E-02
     FORCE CONVERGENCE VALUE  =  0.3051E-01  CRITERION=   3.787     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.9014E-02  CRITERION=   3.475     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   2
 *** LOAD STEP     1   SUBSTEP     7  COMPLETED.    CUM ITER =     11
 *** TIME =  0.217813         TIME INC =  0.759375E-01
 *** AUTO TIME STEP:  NEXT TIME INC = 0.10000      INCREASED (FACTOR = 1.3169)

     FORCE CONVERGENCE VALUE  =   781.3      CRITERION=   5.525
     MOMENT CONVERGENCE VALUE =   79.26      CRITERION=   5.071
     DISP CONVERGENCE VALUE   =  0.1687      CRITERION=  0.2356E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1687
     FORCE CONVERGENCE VALUE  =   177.9      CRITERION=   5.526
     MOMENT CONVERGENCE VALUE =   11.17      CRITERION=   5.071
     DISP CONVERGENCE VALUE   =  0.2494E-01  CRITERION=  0.2481E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2494E-01
     FORCE CONVERGENCE VALUE  =   3.277      CRITERION=   5.526     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.3322      CRITERION=   5.071     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.8120E-03  CRITERION=  0.2484E-01 <<< CONVERGED
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC = -0.8120E-03
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   3
 *** LOAD STEP     1   SUBSTEP     8  COMPLETED.    CUM ITER =     14
 *** TIME =  0.317813         TIME INC =  0.100000
 *** AUTO STEP TIME:  NEXT TIME INC = 0.10000      UNCHANGED

     FORCE CONVERGENCE VALUE  =   2522.      CRITERION=   7.264
     MOMENT CONVERGENCE VALUE =   157.6      CRITERION=   6.666
     DISP CONVERGENCE VALUE   =  0.3201      CRITERION=  0.3187E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3201
     FORCE CONVERGENCE VALUE  =   802.8      CRITERION=   7.265
     MOMENT CONVERGENCE VALUE =   48.60      CRITERION=   6.667
     DISP CONVERGENCE VALUE   =  0.1286      CRITERION=  0.3533E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1286
     FORCE CONVERGENCE VALUE  =   71.58      CRITERION=   7.265
     MOMENT CONVERGENCE VALUE =   5.723      CRITERION=   6.667     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.4113E-01  CRITERION=  0.3557E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.4113E-01
     FORCE CONVERGENCE VALUE  =   4.570      CRITERION=   7.265     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.3269      CRITERION=   6.667     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1397E-02  CRITERION=  0.3557E-01 <<< CONVERGED
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC =  0.1397E-02
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   4
 *** LOAD STEP     1   SUBSTEP     9  COMPLETED.    CUM ITER =     18
 *** TIME =  0.417813         TIME INC =  0.100000
 *** AUTO STEP TIME:  NEXT TIME INC = 0.10000      UNCHANGED

     FORCE CONVERGENCE VALUE  =   9178.      CRITERION=   9.006
     MOMENT CONVERGENCE VALUE =   777.1      CRITERION=   8.264
     DISP CONVERGENCE VALUE   =  0.8389      CRITERION=  0.6052E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.8389
     FORCE CONVERGENCE VALUE  =   3620.      CRITERION=   9.008
     MOMENT CONVERGENCE VALUE =   267.5      CRITERION=   8.266
     DISP CONVERGENCE VALUE   =  0.6188      CRITERION=  0.7166E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.6188
     FORCE CONVERGENCE VALUE  =   1032.      CRITERION=   9.010
     MOMENT CONVERGENCE VALUE =   89.59      CRITERION=   8.268
     DISP CONVERGENCE VALUE   =   1.023      CRITERION=  0.9582E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  -1.023
     FORCE CONVERGENCE VALUE  =   3337.      CRITERION=   9.011
     MOMENT CONVERGENCE VALUE =   313.5      CRITERION=   8.269
     DISP CONVERGENCE VALUE   =  0.1755      CRITERION=  0.9586E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1755
     FORCE CONVERGENCE VALUE  =   142.2      CRITERION=   9.011
     MOMENT CONVERGENCE VALUE =   44.23      CRITERION=   8.270
     DISP CONVERGENCE VALUE   =  0.3050      CRITERION=  0.9623E-01
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3050
     FORCE CONVERGENCE VALUE  =   246.8      CRITERION=   9.012
     MOMENT CONVERGENCE VALUE =   18.13      CRITERION=   8.270
     DISP CONVERGENCE VALUE   =  0.2704      CRITERION=  0.9628E-01
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2704
     FORCE CONVERGENCE VALUE  =   243.5      CRITERION=   9.012
     MOMENT CONVERGENCE VALUE =   17.49      CRITERION=   8.270
     DISP CONVERGENCE VALUE   =  0.9261      CRITERION=  0.9628E-01
    EQUIL ITER   7 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.9261
     FORCE CONVERGENCE VALUE  =   2146.      CRITERION=   10.59
     MOMENT CONVERGENCE VALUE =   238.1      CRITERION=   9.720
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   8
 *** LOAD STEP     1   SUBSTEP    10  NOT COMPLETED.  CUM ITER =     26
 *** BEGIN BISECTION NUMBER   1    NEW TIME INCREMENT=  0.45000E-01

     FORCE CONVERGENCE VALUE  =   2995.      CRITERION=   8.048
     MOMENT CONVERGENCE VALUE =   194.5      CRITERION=   7.386
     DISP CONVERGENCE VALUE   =  0.3766      CRITERION=  0.3557E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3766
     FORCE CONVERGENCE VALUE  =   496.4      CRITERION=   8.049
     MOMENT CONVERGENCE VALUE =   33.11      CRITERION=   7.386
     DISP CONVERGENCE VALUE   =  0.1569      CRITERION=  0.3743E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1569
     FORCE CONVERGENCE VALUE  =   105.3      CRITERION=   8.050
     MOMENT CONVERGENCE VALUE =   7.260      CRITERION=   7.387     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.6500E-01  CRITERION=  0.3929E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.6500E-01
     FORCE CONVERGENCE VALUE  =   16.99      CRITERION=   8.050
     MOMENT CONVERGENCE VALUE =   1.221      CRITERION=   7.387     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1541E-01  CRITERION=  0.3939E-01 <<< CONVERGED
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1541E-01
     FORCE CONVERGENCE VALUE  =  0.8279      CRITERION=   8.050     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.1052      CRITERION=   7.387     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   4
 *** LOAD STEP     1   SUBSTEP    10  COMPLETED.    CUM ITER =     29
 *** TIME =  0.462813         TIME INC =  0.450000E-01
 *** AUTO STEP TIME:  NEXT TIME INC = 0.45000E-01  UNCHANGED

     FORCE CONVERGENCE VALUE  =   5962.      CRITERION=   8.835
     MOMENT CONVERGENCE VALUE =   543.9      CRITERION=   8.107
     DISP CONVERGENCE VALUE   =  0.6835      CRITERION=  0.5040E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.6835
     FORCE CONVERGENCE VALUE  =   1134.      CRITERION=   8.835
     MOMENT CONVERGENCE VALUE =   90.52      CRITERION=   8.108
     DISP CONVERGENCE VALUE   =  0.5647      CRITERION=  0.6684E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.5647
     FORCE CONVERGENCE VALUE  =   1111.      CRITERION=   8.836
     MOMENT CONVERGENCE VALUE =   74.43      CRITERION=   8.109
     DISP CONVERGENCE VALUE   =  0.1671      CRITERION=  0.7284E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1671
     FORCE CONVERGENCE VALUE  =   105.0      CRITERION=   8.836
     MOMENT CONVERGENCE VALUE =   9.946      CRITERION=   8.109
     DISP CONVERGENCE VALUE   =  0.7323E-01  CRITERION=  0.7417E-01 <<< CONVERGED
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.7323E-01
     FORCE CONVERGENCE VALUE  =   22.34      CRITERION=   8.836
     MOMENT CONVERGENCE VALUE =   1.546      CRITERION=   8.109     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.4771E-02  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.4771E-02
     FORCE CONVERGENCE VALUE  =  0.1063      CRITERION=   8.836     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.1221      CRITERION=   8.109     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   5
 *** LOAD STEP     1   SUBSTEP    11  COMPLETED.    CUM ITER =     34
 *** TIME =  0.507812         TIME INC =  0.450000E-01
 *** AUTO TIME STEP:  NEXT TIME INC = 0.67500E-01  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =  0.3334E+05  CRITERION=   10.02
     MOMENT CONVERGENCE VALUE =   7795.      CRITERION=   9.195
     DISP CONVERGENCE VALUE   =   1.683      CRITERION=  0.8513E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   1.683
     FORCE CONVERGENCE VALUE  =  0.3672E+05  CRITERION=   10.02
     MOMENT CONVERGENCE VALUE =  0.1468E+05  CRITERION=   9.198
     DISP CONVERGENCE VALUE   =   7.150      CRITERION=  0.2864
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   7.150
     FORCE CONVERGENCE VALUE  =  0.1337E+06  CRITERION=   10.09
     MOMENT CONVERGENCE VALUE =  0.6255E+06  CRITERION=   9.261
     DISP CONVERGENCE VALUE   =   380.7      CRITERION=   18.90
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  -380.7
     FORCE CONVERGENCE VALUE  =  0.4605E+07  CRITERION=   84.79
     MOMENT CONVERGENCE VALUE =  0.2265E+08  CRITERION=   77.81
     DISP CONVERGENCE VALUE   =  0.1374E+05  CRITERION=   703.1
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1374E+05

 *** ERROR ***                           CP =       0.000   TIME= 00:00:00
 Element 17426 has excessive thickness change.

 *** ERROR ***                           CP =       0.000   TIME= 00:00:00
 Element 2517 has excessive thickness change.
 *** LOAD STEP     1   SUBSTEP    12  NOT COMPLETED.  CUM ITER =     39
 *** BEGIN BISECTION NUMBER   1    NEW TIME INCREMENT=  0.23625E-01

     FORCE CONVERGENCE VALUE  =   7739.      CRITERION=   9.250
     MOMENT CONVERGENCE VALUE =   1071.      CRITERION=   8.489
     DISP CONVERGENCE VALUE   =  0.3148      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3148
     FORCE CONVERGENCE VALUE  =   521.2      CRITERION=   9.250
     MOMENT CONVERGENCE VALUE =   168.1      CRITERION=   8.489
     DISP CONVERGENCE VALUE   =   3.185      CRITERION=  0.1758
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   3.185
     FORCE CONVERGENCE VALUE  =  0.1925E+05  CRITERION=   9.252
     MOMENT CONVERGENCE VALUE =   6530.      CRITERION=   8.490
     DISP CONVERGENCE VALUE   =   2.477      CRITERION=  0.1758
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   2.477
     FORCE CONVERGENCE VALUE  =  0.2903E+05  CRITERION=   9.255
     MOMENT CONVERGENCE VALUE =  0.3408E+05  CRITERION=   8.493
     DISP CONVERGENCE VALUE   =   9.697      CRITERION=  0.5765
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   9.697
     FORCE CONVERGENCE VALUE  =  0.5777E+06  CRITERION=   9.488
     MOMENT CONVERGENCE VALUE =  0.2332E+07  CRITERION=   8.707
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   5
 *** LOAD STEP     1   SUBSTEP    12  NOT COMPLETED.  CUM ITER =     43
 *** BEGIN BISECTION NUMBER   2    NEW TIME INCREMENT=  0.10631E-01

     FORCE CONVERGENCE VALUE  =   2830.      CRITERION=   9.023
     MOMENT CONVERGENCE VALUE =   316.6      CRITERION=   8.280
     DISP CONVERGENCE VALUE   =  0.1987      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1987
     FORCE CONVERGENCE VALUE  =   150.4      CRITERION=   9.023
     MOMENT CONVERGENCE VALUE =   40.22      CRITERION=   8.280
     DISP CONVERGENCE VALUE   =  0.2897      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2897
     FORCE CONVERGENCE VALUE  =   259.6      CRITERION=   9.023
     MOMENT CONVERGENCE VALUE =   18.92      CRITERION=   8.280
     DISP CONVERGENCE VALUE   =  0.4809      CRITERION=  0.7422E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.4809
     FORCE CONVERGENCE VALUE  =   690.2      CRITERION=   9.023
     MOMENT CONVERGENCE VALUE =   46.30      CRITERION=   8.280
     DISP CONVERGENCE VALUE   =   1.755      CRITERION=  0.1271
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   1.755
     FORCE CONVERGENCE VALUE  =   6684.      CRITERION=   9.024
     MOMENT CONVERGENCE VALUE =   973.2      CRITERION=   8.281
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   5
 *** LOAD STEP     1   SUBSTEP    12  NOT COMPLETED.  CUM ITER =     47
 *** BEGIN BISECTION NUMBER   3    NEW TIME INCREMENT=  0.47841E-02

     FORCE CONVERGENCE VALUE  =   1140.      CRITERION=   8.920
     MOMENT CONVERGENCE VALUE =   114.9      CRITERION=   8.186
     DISP CONVERGENCE VALUE   =  0.1121      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1121
     FORCE CONVERGENCE VALUE  =   42.68      CRITERION=   8.920
     MOMENT CONVERGENCE VALUE =   8.289      CRITERION=   8.186
     DISP CONVERGENCE VALUE   =  0.7531E-01  CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.7531E-01
     FORCE CONVERGENCE VALUE  =   16.17      CRITERION=   8.920
     MOMENT CONVERGENCE VALUE =   1.451      CRITERION=   8.186     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1739E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1739E-01
     FORCE CONVERGENCE VALUE  =   1.085      CRITERION=   8.920     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.2552      CRITERION=   8.186     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   3
 *** LOAD STEP     1   SUBSTEP    12  COMPLETED.    CUM ITER =     49
 *** TIME =  0.512597         TIME INC =  0.478406E-02
 *** AUTO STEP TIME:  NEXT TIME INC = 0.47841E-02  UNCHANGED

     FORCE CONVERGENCE VALUE  =   437.0      CRITERION=   9.004
     MOMENT CONVERGENCE VALUE =   32.47      CRITERION=   8.263
     DISP CONVERGENCE VALUE   =  0.1258      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1258
     FORCE CONVERGENCE VALUE  =   56.91      CRITERION=   9.004
     MOMENT CONVERGENCE VALUE =   5.574      CRITERION=   8.263     <<< CONVERGED
     DISP CONVERGENCE VALUE   =   1.113      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  -1.113
     FORCE CONVERGENCE VALUE  =   4126.      CRITERION=   9.004
     MOMENT CONVERGENCE VALUE =   575.1      CRITERION=   8.263
     DISP CONVERGENCE VALUE   =  0.3482      CRITERION=  0.7422E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3482
     FORCE CONVERGENCE VALUE  =   202.8      CRITERION=   9.004
     MOMENT CONVERGENCE VALUE =   90.86      CRITERION=   8.262
     DISP CONVERGENCE VALUE   =  0.3248      CRITERION=  0.7422E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.3248
     FORCE CONVERGENCE VALUE  =   703.1      CRITERION=   9.004
     MOMENT CONVERGENCE VALUE =   63.27      CRITERION=   8.262
     DISP CONVERGENCE VALUE   =  0.1437      CRITERION=  0.7422E-01
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1437
     FORCE CONVERGENCE VALUE  =   67.13      CRITERION=   9.004
     MOMENT CONVERGENCE VALUE =   12.22      CRITERION=   8.263
     DISP CONVERGENCE VALUE   =  0.2515      CRITERION=  0.7422E-01
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2515
     FORCE CONVERGENCE VALUE  =   225.4      CRITERION=   9.004
     MOMENT CONVERGENCE VALUE =   17.31      CRITERION=   8.263
     DISP CONVERGENCE VALUE   =  0.1216      CRITERION=  0.7422E-01
    EQUIL ITER   7 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1216
     FORCE CONVERGENCE VALUE  =   57.19      CRITERION=   10.58
     MOMENT CONVERGENCE VALUE =   5.638      CRITERION=   9.712     <<< CONVERGED
     DISP CONVERGENCE VALUE   =   1.048      CRITERION=  0.7422E-01
    EQUIL ITER   8 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   1.048
     FORCE CONVERGENCE VALUE  =   4350.      CRITERION=   10.80
     MOMENT CONVERGENCE VALUE =   481.8      CRITERION=   9.911
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   9
 *** LOAD STEP     1   SUBSTEP    13  NOT COMPLETED.  CUM ITER =     58
 *** BEGIN BISECTION NUMBER   1    NEW TIME INCREMENT=  0.21528E-02

     FORCE CONVERGENCE VALUE  =   143.3      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   9.974      CRITERION=   8.220
     DISP CONVERGENCE VALUE   =  0.4821E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.4821E-01
     FORCE CONVERGENCE VALUE  =   10.86      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   1.356      CRITERION=   8.220     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.7755E-01  CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.7755E-01
     FORCE CONVERGENCE VALUE  =   22.42      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   1.937      CRITERION=   8.221     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.5666E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.5666E-01
     FORCE CONVERGENCE VALUE  =   13.12      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   1.281      CRITERION=   8.221     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1207      CRITERION=  0.7422E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1207
     FORCE CONVERGENCE VALUE  =   55.45      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   4.396      CRITERION=   8.221     <<< CONVERGED
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   5
 *** LOAD STEP     1   SUBSTEP    13  NOT COMPLETED.  CUM ITER =     62
 *** BEGIN BISECTION NUMBER   2    NEW TIME INCREMENT=  0.96877E-03

     FORCE CONVERGENCE VALUE  =   54.02      CRITERION=   8.937
     MOMENT CONVERGENCE VALUE =   3.686      CRITERION=   8.201
     DISP CONVERGENCE VALUE   =  0.2413E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2413E-01
     FORCE CONVERGENCE VALUE  =   2.383      CRITERION=   8.937     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.4496      CRITERION=   8.201     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   1
 *** LOAD STEP     1   SUBSTEP    13  COMPLETED.    CUM ITER =     62
 *** TIME =  0.513565         TIME INC =  0.968773E-03
 *** AUTO STEP TIME:  NEXT TIME INC = 0.96877E-03  UNCHANGED

     FORCE CONVERGENCE VALUE  =   39.63      CRITERION=   8.954
     MOMENT CONVERGENCE VALUE =   2.841      CRITERION=   8.217
     DISP CONVERGENCE VALUE   =  0.3882E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3882E-01
     FORCE CONVERGENCE VALUE  =   6.308      CRITERION=   8.954     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.7885      CRITERION=   8.217     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   1
 *** LOAD STEP     1   SUBSTEP    14  COMPLETED.    CUM ITER =     63
 *** TIME =  0.514534         TIME INC =  0.968773E-03
 *** AUTO TIME STEP:  NEXT TIME INC = 0.14532E-02  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =   177.7      CRITERION=   8.980
     MOMENT CONVERGENCE VALUE =   13.17      CRITERION=   8.240
     DISP CONVERGENCE VALUE   =  0.3462      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3462
     FORCE CONVERGENCE VALUE  =   348.9      CRITERION=   8.980
     MOMENT CONVERGENCE VALUE =   22.75      CRITERION=   8.241
     DISP CONVERGENCE VALUE   =   1.482      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  -1.482
     FORCE CONVERGENCE VALUE  =   5235.      CRITERION=   8.980
     MOMENT CONVERGENCE VALUE =   761.6      CRITERION=   8.240
     DISP CONVERGENCE VALUE   =  0.3994      CRITERION=  0.7422E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3994
     FORCE CONVERGENCE VALUE  =   250.6      CRITERION=   8.979
     MOMENT CONVERGENCE VALUE =   109.2      CRITERION=   8.240
     DISP CONVERGENCE VALUE   =  0.2678      CRITERION=  0.7422E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2678
     FORCE CONVERGENCE VALUE  =   374.0      CRITERION=   8.979
     MOMENT CONVERGENCE VALUE =   40.17      CRITERION=   8.240
     DISP CONVERGENCE VALUE   =  0.1573      CRITERION=  0.7422E-01
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1573
     FORCE CONVERGENCE VALUE  =   85.54      CRITERION=   8.980
     MOMENT CONVERGENCE VALUE =   11.95      CRITERION=   8.240
     DISP CONVERGENCE VALUE   =  0.1360      CRITERION=  0.7422E-01
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1360
     FORCE CONVERGENCE VALUE  =   86.90      CRITERION=   8.980
     MOMENT CONVERGENCE VALUE =   7.445      CRITERION=   8.240     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1102      CRITERION=  0.7422E-01
    EQUIL ITER   7 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1102
     FORCE CONVERGENCE VALUE  =   53.46      CRITERION=   10.55
     MOMENT CONVERGENCE VALUE =   4.531      CRITERION=   9.686     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2589      CRITERION=  0.7422E-01
    EQUIL ITER   8 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2589
     FORCE CONVERGENCE VALUE  =   268.2      CRITERION=   10.77
     MOMENT CONVERGENCE VALUE =   19.45      CRITERION=   9.884
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   9
 *** LOAD STEP     1   SUBSTEP    15  NOT COMPLETED.  CUM ITER =     72
 *** BEGIN BISECTION NUMBER   1    NEW TIME INCREMENT=  0.65392E-03

     FORCE CONVERGENCE VALUE  =   58.54      CRITERION=   8.966
     MOMENT CONVERGENCE VALUE =   4.289      CRITERION=   8.228
     DISP CONVERGENCE VALUE   =  0.1294      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1294
     FORCE CONVERGENCE VALUE  =   61.77      CRITERION=   8.966
     MOMENT CONVERGENCE VALUE =   4.735      CRITERION=   8.228     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2145      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2145
     FORCE CONVERGENCE VALUE  =   143.2      CRITERION=   8.966
     MOMENT CONVERGENCE VALUE =   10.70      CRITERION=   8.228
     DISP CONVERGENCE VALUE   =  0.6552E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.6552E-01
     FORCE CONVERGENCE VALUE  =   10.25      CRITERION=   8.966
     MOMENT CONVERGENCE VALUE =   1.454      CRITERION=   8.228     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2108      CRITERION=  0.7422E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2108
     FORCE CONVERGENCE VALUE  =   196.7      CRITERION=   8.966
     MOMENT CONVERGENCE VALUE =   14.50      CRITERION=   8.228
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   5
 *** LOAD STEP     1   SUBSTEP    15  NOT COMPLETED.  CUM ITER =     76
 *** BEGIN BISECTION NUMBER   2    NEW TIME INCREMENT=  0.29426E-03

     FORCE CONVERGENCE VALUE  =   24.66      CRITERION=   8.959
     MOMENT CONVERGENCE VALUE =   1.900      CRITERION=   8.222
     DISP CONVERGENCE VALUE   =  0.6161E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.6161E-01
     FORCE CONVERGENCE VALUE  =   16.81      CRITERION=   8.959
     MOMENT CONVERGENCE VALUE =   1.550      CRITERION=   8.222     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.3000      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.3000
     FORCE CONVERGENCE VALUE  =   345.4      CRITERION=   8.959
     MOMENT CONVERGENCE VALUE =   28.45      CRITERION=   8.222
     DISP CONVERGENCE VALUE   =  0.9271E-01  CRITERION=  0.7422E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.9271E-01
     FORCE CONVERGENCE VALUE  =   21.13      CRITERION=   8.959
     MOMENT CONVERGENCE VALUE =   3.953      CRITERION=   8.222     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1182      CRITERION=  0.7422E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1182
     FORCE CONVERGENCE VALUE  =   53.95      CRITERION=   8.959
     MOMENT CONVERGENCE VALUE =   4.324      CRITERION=   8.222     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.5180E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.5180E-01
     FORCE CONVERGENCE VALUE  =   10.69      CRITERION=   8.959
     MOMENT CONVERGENCE VALUE =   1.181      CRITERION=   8.222     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.7971E-01  CRITERION=  0.7422E-01
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.7971E-01
     FORCE CONVERGENCE VALUE  =   27.32      CRITERION=   8.959
     MOMENT CONVERGENCE VALUE =   2.305      CRITERION=   8.222     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2621      CRITERION=  0.7422E-01
    EQUIL ITER   7 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2621
     FORCE CONVERGENCE VALUE  =   255.6      CRITERION=   10.53
     MOMENT CONVERGENCE VALUE =   20.50      CRITERION=   9.664
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =   8
 *** LOAD STEP     1   SUBSTEP    15  NOT COMPLETED.  CUM ITER =     83
 *** BEGIN BISECTION NUMBER   3    NEW TIME INCREMENT=  0.10000E-03

     FORCE CONVERGENCE VALUE  =   11.54      CRITERION=   8.956
     MOMENT CONVERGENCE VALUE =   1.060      CRITERION=   8.219
     DISP CONVERGENCE VALUE   =  0.4012E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.4012E-01
     FORCE CONVERGENCE VALUE  =   6.714      CRITERION=   8.956     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.7801      CRITERION=   8.219     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   1
 *** LOAD STEP     1   SUBSTEP    15  COMPLETED.    CUM ITER =     83
 *** TIME =  0.514634         TIME INC =  0.100000E-03
 *** AUTO STEP TIME:  NEXT TIME INC = 0.10000E-03  UNCHANGED

     FORCE CONVERGENCE VALUE  =   28.39      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   2.158      CRITERION=   8.220
     DISP CONVERGENCE VALUE   =  0.5154      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.5154
     FORCE CONVERGENCE VALUE  =   996.2      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   93.89      CRITERION=   8.220
     DISP CONVERGENCE VALUE   =  0.1513      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1513
     FORCE CONVERGENCE VALUE  =   46.69      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   14.29      CRITERION=   8.220
     DISP CONVERGENCE VALUE   =  0.1749      CRITERION=  0.7422E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1749
     FORCE CONVERGENCE VALUE  =   129.2      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   10.61      CRITERION=   8.220
     DISP CONVERGENCE VALUE   =  0.6899E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.6899E-01
     FORCE CONVERGENCE VALUE  =   19.35      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   2.207      CRITERION=   8.220     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.8524E-01  CRITERION=  0.7422E-01
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.8524E-01
     FORCE CONVERGENCE VALUE  =   27.44      CRITERION=   8.958
     MOMENT CONVERGENCE VALUE =   2.327      CRITERION=   8.220     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.4444E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.4444E-01
     FORCE CONVERGENCE VALUE  =   8.756      CRITERION=   8.958     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.9666      CRITERION=   8.220     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   6
 *** LOAD STEP     1   SUBSTEP    16  COMPLETED.    CUM ITER =     89
 *** TIME =  0.514734         TIME INC =  0.100000E-03
 *** AUTO STEP TIME:  NEXT TIME INC = 0.10000E-03  UNCHANGED

     FORCE CONVERGENCE VALUE  =   10.90      CRITERION=   8.960
     MOMENT CONVERGENCE VALUE =   1.171      CRITERION=   8.222
     DISP CONVERGENCE VALUE   =  0.1377      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1377
     FORCE CONVERGENCE VALUE  =   82.42      CRITERION=   8.960
     MOMENT CONVERGENCE VALUE =   6.212      CRITERION=   8.222     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.2067      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2067
     FORCE CONVERGENCE VALUE  =   135.0      CRITERION=   8.960
     MOMENT CONVERGENCE VALUE =   10.00      CRITERION=   8.222
     DISP CONVERGENCE VALUE   =  0.4928E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.4928E-01
     FORCE CONVERGENCE VALUE  =   5.373      CRITERION=   8.960     <<< CONVERGED
     MOMENT CONVERGENCE VALUE =  0.8629      CRITERION=   8.222     <<< CONVERGED
    >>> SOLUTION CONVERGED AFTER EQUILIBRIUM ITERATION   3
 *** LOAD STEP     1   SUBSTEP    17  COMPLETED.    CUM ITER =     92
 *** TIME =  0.514834         TIME INC =  0.100000E-03
 *** AUTO TIME STEP:  NEXT TIME INC = 0.15000E-03  INCREASED (FACTOR = 1.5000)

     FORCE CONVERGENCE VALUE  =   13.64      CRITERION=   8.962
     MOMENT CONVERGENCE VALUE =   2.192      CRITERION=   8.224
     DISP CONVERGENCE VALUE   =  0.1057      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1057
     FORCE CONVERGENCE VALUE  =   46.42      CRITERION=   8.962
     MOMENT CONVERGENCE VALUE =   3.675      CRITERION=   8.224     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.9430      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.9430
     FORCE CONVERGENCE VALUE  =   3204.      CRITERION=   8.962
     MOMENT CONVERGENCE VALUE =   398.8      CRITERION=   8.224
     DISP CONVERGENCE VALUE   =  0.2859      CRITERION=  0.7422E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.2859
     FORCE CONVERGENCE VALUE  =   146.8      CRITERION=   8.962
     MOMENT CONVERGENCE VALUE =   61.78      CRITERION=   8.224
     DISP CONVERGENCE VALUE   =  0.2422      CRITERION=  0.7422E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2422
     FORCE CONVERGENCE VALUE  =   455.6      CRITERION=   8.962
     MOMENT CONVERGENCE VALUE =   40.41      CRITERION=   8.224
     DISP CONVERGENCE VALUE   =  0.1148      CRITERION=  0.7422E-01
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1148
     FORCE CONVERGENCE VALUE  =   49.29      CRITERION=   8.962
     MOMENT CONVERGENCE VALUE =   7.475      CRITERION=   8.224     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1648      CRITERION=  0.7422E-01
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1648
     FORCE CONVERGENCE VALUE  =   96.52      CRITERION=   8.962
     MOMENT CONVERGENCE VALUE =   7.504      CRITERION=   8.224     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.6973E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   7 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.6973E-01
     FORCE CONVERGENCE VALUE  =   21.02      CRITERION=   10.53
     MOMENT CONVERGENCE VALUE =   2.113      CRITERION=   9.667     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.9208E-01  CRITERION=  0.7422E-01
    EQUIL ITER   8 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.9208E-01
     FORCE CONVERGENCE VALUE  =   32.98      CRITERION=   10.75
     MOMENT CONVERGENCE VALUE =   2.723      CRITERION=   9.864     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1312      CRITERION=  0.7422E-01
    EQUIL ITER   9 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1312
     FORCE CONVERGENCE VALUE  =   67.80      CRITERION=   10.97
     MOMENT CONVERGENCE VALUE =   5.182      CRITERION=   10.07     <<< CONVERGED
    >>> SOLUTION PATTERNS SHOW DIVERGENCE AT ITERATION =  10
 *** LOAD STEP     1   SUBSTEP    18  NOT COMPLETED.  CUM ITER =    102
 *** BEGIN BISECTION NUMBER   1    NEW TIME INCREMENT=  0.10000E-03

     FORCE CONVERGENCE VALUE  =   10.10      CRITERION=   8.961
     MOMENT CONVERGENCE VALUE =   1.683      CRITERION=   8.223
     DISP CONVERGENCE VALUE   =  0.1036      CRITERION=  0.7422E-01
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1036
     FORCE CONVERGENCE VALUE  =   44.92      CRITERION=   8.961
     MOMENT CONVERGENCE VALUE =   3.556      CRITERION=   8.224     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.3994      CRITERION=  0.7422E-01
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.3994
     FORCE CONVERGENCE VALUE  =   577.0      CRITERION=   8.961
     MOMENT CONVERGENCE VALUE =   49.52      CRITERION=   8.223
     DISP CONVERGENCE VALUE   =  0.1151      CRITERION=  0.7422E-01
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1151
     FORCE CONVERGENCE VALUE  =   28.35      CRITERION=   8.961
     MOMENT CONVERGENCE VALUE =   6.978      CRITERION=   8.223     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1348      CRITERION=  0.7422E-01
    EQUIL ITER   4 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1348
     FORCE CONVERGENCE VALUE  =   74.52      CRITERION=   8.961
     MOMENT CONVERGENCE VALUE =   6.026      CRITERION=   8.223     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.6109E-01  CRITERION=  0.7422E-01 <<< CONVERGED
    EQUIL ITER   5 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.6109E-01
     FORCE CONVERGENCE VALUE  =   14.38      CRITERION=   8.961
     MOMENT CONVERGENCE VALUE =   1.547      CRITERION=   8.223     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.8651E-01  CRITERION=  0.7422E-01
    EQUIL ITER   6 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.8651E-01
     FORCE CONVERGENCE VALUE  =   31.28      CRITERION=   8.961
     MOMENT CONVERGENCE VALUE =   2.604      CRITERION=   8.223     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.9241      CRITERION=  0.7422E-01
    EQUIL ITER   7 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.9241
     FORCE CONVERGENCE VALUE  =   3187.      CRITERION=   10.53
     MOMENT CONVERGENCE VALUE =   317.2      CRITERION=   9.666
     DISP CONVERGENCE VALUE   =  0.3616      CRITERION=  0.7422E-01
    EQUIL ITER   8 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.3616
     FORCE CONVERGENCE VALUE  =   279.6      CRITERION=   10.75
     MOMENT CONVERGENCE VALUE =   45.13      CRITERION=   9.864
     DISP CONVERGENCE VALUE   =   1.388      CRITERION=  0.1293
    EQUIL ITER   9 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   1.388
     FORCE CONVERGENCE VALUE  =   6388.      CRITERION=   10.97
     MOMENT CONVERGENCE VALUE =   901.9      CRITERION=   10.07
     DISP CONVERGENCE VALUE   =  0.2434      CRITERION=  0.1293
    EQUIL ITER  10 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2434
     FORCE CONVERGENCE VALUE  =   397.3      CRITERION=   11.19
     MOMENT CONVERGENCE VALUE =   150.2      CRITERION=   10.27
     DISP CONVERGENCE VALUE   =  0.8643      CRITERION=  0.1293
    EQUIL ITER  11 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.8643
     FORCE CONVERGENCE VALUE  =   1849.      CRITERION=   11.42
     MOMENT CONVERGENCE VALUE =   175.5      CRITERION=   10.48
     DISP CONVERGENCE VALUE   =  0.1396      CRITERION=  0.1293
    EQUIL ITER  12 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1396
     FORCE CONVERGENCE VALUE  =   84.71      CRITERION=   11.66
     MOMENT CONVERGENCE VALUE =   32.81      CRITERION=   10.70
     DISP CONVERGENCE VALUE   =  0.2072      CRITERION=  0.1293
    EQUIL ITER  13 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.2072
     FORCE CONVERGENCE VALUE  =   103.4      CRITERION=   11.89
     MOMENT CONVERGENCE VALUE =   8.223      CRITERION=   10.91     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.1151      CRITERION=  0.1293     <<< CONVERGED
    EQUIL ITER  14 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.1151
     FORCE CONVERGENCE VALUE  =   29.64      CRITERION=   12.14
     MOMENT CONVERGENCE VALUE =   2.837      CRITERION=   11.14     <<< CONVERGED
     DISP CONVERGENCE VALUE   =  0.7430E-01  CRITERION=  0.1293     <<< CONVERGED
    EQUIL ITER  15 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC= -0.7430E-01
     FORCE CONVERGENCE VALUE  =   12.61      CRITERION=   12.38
     MOMENT CONVERGENCE VALUE =   1.019      CRITERION=   11.36     <<< CONVERGED

 *** WARNING ***                         CP =       0.000   TIME= 00:00:00
 Solution not converged at time 0.514934108 (load step 1 substep 18).
  Run continued at user request.
 *** LOAD STEP     1   SUBSTEP    18  COMPLETED.    CUM ITER =    116
 *** TIME =  0.514934         TIME INC =  0.100000E-03
 *** MAX PLASTIC STRAIN STEP = 0.1223E-04   CRITERION = 0.1500
 *** AUTO STEP TIME:  NEXT TIME INC = 0.10000E-03  UNCHANGED

     FORCE CONVERGENCE VALUE  =  0.1381E+06  CRITERION=   8.966
     MOMENT CONVERGENCE VALUE =  0.2126E+07  CRITERION=   8.228
     DISP CONVERGENCE VALUE   =   38.66      CRITERION=   1.929
    EQUIL ITER   1 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  -38.66
     FORCE CONVERGENCE VALUE  =  0.1716E+07  CRITERION=   10.01
     MOMENT CONVERGENCE VALUE =  0.1078E+08  CRITERION=   9.188
     DISP CONVERGENCE VALUE   =   4183.      CRITERION=   209.2
    EQUIL ITER   2 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=   4183.
     FORCE CONVERGENCE VALUE  =  0.1094E+08  CRITERION=   8790.
     MOMENT CONVERGENCE VALUE =  0.6503E+08  CRITERION=   8067.
     DISP CONVERGENCE VALUE   =  0.1526E+06  CRITERION=   7739.
    EQUIL ITER   3 COMPLETED.  NEW TRIANG MATRIX.  MAX DOF INC=  0.1934E+06

 *** ERROR ***                           CP =       0.000   TIME= 00:00:00
 Element 19905 has excessive thickness change.

 *** ERROR ***                           CP =       0.000   TIME= 00:00:00
 Element 3389 has excessive thickness change.

 *** ERROR ***                           CP =       0.000   TIME= 00:00:00
 Element 0 (type = 1, SHELL281) (and maybe other elements) has become
 highly distorted.  Excessive distortion of elements is usually a
 symptom indicating the need for corrective action elsewhere.  Try
 incrementing the load more slowly (increase the number of substeps or
 decrease the time step size).  You may need to improve your mesh to
 obtain elements with better aspect ratios.  Also consider the behavior
 of materials, contact pairs, and/or constraint equations.  Please rule
 out other root causes of this failure before attempting rezoning or
 nonlinear adaptive solutions.  If this message appears in the first
 iteration of first substep, be sure to perform element shape checking.

 *** WARNING ***                         CP =       0.000   TIME= 00:00:00
 The unconverged solution (identified as time 1 substep 999999) is
 output for analysis debug purposes.  Results should not be used for
 any other purpose.




         R E S T A R T   I N F O R M A T I O N

 REASON FOR TERMINATION. . . . . . . . . .ERROR IN ELEMENT FORMULATION
 FILES NEEDED FOR RESTARTING . . . . . . .  buckling0.Rnnn
                                            buckling.ldhi
                                            buckling.rdb
 TIME OF LAST SOLUTION . . . . . . . . . . 0.51493
    TIME AT START OF THE LOAD STEP . . . .  0.0000
    TIME AT END OF THE LOAD STEP . . . . .  1.0000

 ALL CURRENT MAPDL DATA WRITTEN TO FILE NAME=
  FOR POSSIBLE RESUME FROM THIS POINT





 ***** ROUTINE COMPLETED *****  CP =         0.000
End nonlinear static analysis on imperfect geometry

Post-buckling analysis#

An unconverged solution of the nonlinear static analysis could mean that buckling has occurred. In this example, the change in time (or load) increment, and displacement value, occurs between substeps 10 and 11, which corresponds to TIME = 0.51781 and TIME = 0.53806 and to a pressure between 0.124 MPa and 0.129 MPa. It is therefore very likely that buckling occurred at this time; to be sure, the analysis is continued. The goal is to verify the assessment made at this stage by obtaining the load-displacement behavior over a larger range. Because the post-buckling state is unstable, special techniques are necessary to compensate - in this case, nonlinear stabilization is used.

print('Begin post-buckling analysis')

mapdl.slashsolu()  # Restart analysis with stabilization
mapdl.antype("static", "restart", 1, 10)
mapdl.nsubst(100, 50000, 10)
mapdl.rescontrol("define", "last")
mapdl.stabilize("constant", "energy", 0.000145)  # Use energy option
output = mapdl.solve()
mapdl.finish()

print('End of post-buckling analysis run')

Postprocess buckling analysis in POST1#

print('Begin POST1 postprocessing of post-buckling analysis')
mapdl.post1()
mapdl.set("last")
mapdl.post_processing.plot_nodal_displacement("NORM", smooth_shading=True)
mapdl.post_processing.plot_nodal_eqv_stress()
mapdl.finish()
print('End POST1 postprocessing of post-buckling analysis')
  • 21 example technology showcase buckling
  • 21 example technology showcase buckling

Postprocess buckling analysis in POST26#

print('Begin POST26 postprocessing of post-buckling analysis')
mapdl.post26()


mapdl.numvar(100)  # allow storage for 100 variables
mapdl.enersol(13, "sene")  # store stiffness energy
mapdl.enersol(14, "sten")  # store artificial stabilization energy

# time history plot of stiffness and stabilization energies
mapdl.show("png")
mapdl.plvar(13, 14)
mapdl.show("close")

# pressure versus axial shortening for some nodes under the upper ring
mapdl.nsol(2, 67319, "U", "Z", "UZ1")
mapdl.prod(
    ir=3, ia=2, ib="", ic="", name="strain1", facta="", factb="", factc=-1 / 431.8
)
mapdl.prod(ir=12, ia=1, ib="", ic="", name="Load", facta="", factb="", factc=0.24)
mapdl.xvar(3)
mapdl.show("png")
mapdl.xrange(0.01)
mapdl.yrange(0.24)
mapdl.axlab("X", "Axial Shortening")
mapdl.axlab("Y", "Applied Pressure ")
mapdl.plvar(12)
mapdl.show("close")
mapdl.xvar(3)
mapdl.show("png")
mapdl.xrange(0.002)
mapdl.yrange(1)
mapdl.axlab("X", "Axial Shortening")
mapdl.axlab("Y", "Time")
mapdl.plvar(1)
mapdl.show("png")
mapdl.show("close")

# pressure versus radial displacement for the node with max. deformation
mapdl.nsol(6, 65269, "U", "Y", "UY_1")
mapdl.prod(ir=7, ia=6, ib=6, ic="", name="UY2_1")
mapdl.nsol(8, 65269, "U", "X", "UX_1")
mapdl.prod(ir=9, ia=8, ib=8, ic="", name="UX2_1")
mapdl.add(10, 7, 9, "sum")
mapdl.sqrt(ir=11, ia=10, name="Urad")
mapdl.xvar(11)
mapdl.show("png")
mapdl.xrange(4)
mapdl.yrange(0.24)
mapdl.axlab("X", "Radial Displacement")
mapdl.axlab("Y", "Applied Pressure")
mapdl.plvar(12)
mapdl.show("png")
mapdl.show("close")
mapdl.finish()

print('End POST26 postprocessing of post-buckling analysis')
  • 21 example technology showcase buckling
  • 21 example technology showcase buckling
  • 21 example technology showcase buckling
  • 21 example technology showcase buckling

Exit MAPDL#

Exit MAPDL instance.

mapdl.exit()
print("Exited MAPDL")
Exited MAPDL