Mapdl.cncheck(option='', rid1='', rid2='', rinc='', intertype='', trlevel='', cgap='', cpen='', ioff='', **kwargs)

Provides and/or adjusts the initial status of contact pairs.



Option to be performed:

DETAIL - List all contact pair properties (default).

SUMMARY - List only the open/closed status for each contact pair.

POST - Execute a partial solution to write the initial

contact configuration to the Jobname.RCN file.

ADJUST - Physically move contact nodes to the target in

order to close a gap or reduce penetration. The initial adjustment is converted to structural displacement values (UX, UY, UZ) and stored in the Jobname.RCN file.

RESET - Reset target element and contact element key

options and real constants to their default values. This option is not valid for general contact.

AUTO - Automatically sets certain real constants and key

options to recommended values or settings in order to achieve better convergence based on overall contact pair behaviors. This option is not valid for general contact.

TRIM - Trim contact pair (remove certain contact and target elements).

UNSE - Unselect certain contact and target elements.

rid1, rid2, rinc

For pair-based contact, the range of real constant pair ID’s for which Option will be performed. If RID2 is not specified, it defaults to RID1. If no value is specified, all contact pairs in the selected set of elements are considered.


The type of contact interface (pair-based versus general contact) to be considered; or the type of contact pair to be trimmed/unselected/auto-set.

(blank) - Include all contact definitions (pair-based and general contact).

GCN - Include general contact definitions only (not valid

when Option = RESET or AUTO).


Trimming level (used only when Option = TRIM or UNSE):

(blank) - Normal trimming (default): remove/unselect

contact and target elements which are in far-field.

AGGRE - Aggressive trimming: remove/unselect contact and

target elements which are in far-field, and certain elements in near-field.


The CNCHECK command provides information for surface-to-surface, node- to-surface, and line-to-line contact pairs (element types TARGE169, TARGE170, CONTA171, CONTA172, CONTA173, CONTA174, CONTA175, CONTA176, CONTA177). All contact and target elements of interest, along with the solid elements and nodes attached to them, must be selected for the command to function properly. For performance reasons, the program uses a subset of nodes and elements based on the specified contact regions (RID1, RID2, RINC) when executing the CNCHECK command.

CNCHECK is available in both the PREP7 and SOLUTION processors, but only before the first solve operation (that is, only before the first load step or the first substep).

If the contact and target elements were generated through mesh commands (AMESH, LMESH, etc.) instead of the ESURF command, you must issue MODMSH,DETACH before CNCHECK. Otherwise, CNCHECK will not work correctly.

The following additional notes are available:

The command CNCHECK,POST solves the initial contact configuration in one substep. After issuing this command, you can postprocess the contact result items as you would for any other converged load step; however, only the contact status, contact penetration or gap, and contact pressure will have meaningful values. Other contact quantities (friction stress, sliding distance, chattering) will be available but are not useful.

Because Option = POST forces a solve operation, the PrepPost (PP) license does not work with CNCHECK,POST.