cnvtol

Mapdl.cnvtol(lab='', value='', toler='', norm='', minref='', **kwargs)

Sets convergence values for nonlinear analyses.

APDL Command: CNVTOL

Parameters
  • lab – Valid convergence labels. If STAT, list the status of the currently specified criteria.

  • value – Typical reference value for the specified convergence label (Lab).

  • toler – Tolerance; defaults to 0.005 (0.5%) for force and moment, 1.0E-4 (0.01%) for DVOL, 0.05 (5%) for displacement when rotational DOFs are not present, and 0.05 (5%) for HDSP.

  • norm

    Specifies norm selection:

    2 - L2 norm (check SRSS value). Default, except for Lab = U.

    1 - L1 norm (check absolute value sum).

    0 - Infinite norm (check each DOF separately). Default for Lab = U.

  • minref – The minimum value allowed for the program calculated reference value. If negative, no minimum is enforced. Used only if VALUE is blank. Defaults to 0.01 for force, moment, and volume convergence, 1.0E-6 for heat flow, 1.0E-12 for VLTG and CHRG, 1.0E-6 for HDSP, and 0.0 otherwise.

Notes

This command is usually not needed because the default convergence criteria are sufficient for most nonlinear analyses. In rare cases, you may need to use this command to diagnose convergence difficulties.

Values may be set for the degrees of freedom (DOF) and/or the out-of- balance load for the corresponding forcing quantities.

Issuing CNVTOL to set a convergence criterion for a specific convergence label (Lab) does not affect the convergence criterion for any other label. All other convergence criteria will remain at their default setting or at the value set by a previous CNVTOL command.

When the GUI is on, if a “Delete” operation in a Nonlinear Convergence

Criteria dialog box writes this command to a log file (Jobname.LOG or Jobname.LGW), you will observe that Lab is blank, VALUE = -1, and TOLER is an integer number. In this case, the GUI has assigned a value of TOLER that corresponds to the location of a chosen convergence label in the dialog box’s list. It is not intended that you type in such a location value for TOLER in an ANSYS session. However, a file that contains a GUI-generated CNVTOL command of this form can be used for batch input or with the /INPUT command.

Convergence norms specified with CNVTOL may be graphically tracked while the solution is in process using the ANSYS program’s Graphical Solution Tracking (GST) feature. Use the /GST command to turn GST on or off. By default, GST is ON for interactive sessions and OFF for batch runs.

This command is also valid in PREP7.