cncheck#

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

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

APDL Command: CNCHECK

Parameters:
option

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.

  • "MORPH" : Physically move contact nodes to the target in order to close a gap or reduce penetration, and also morph the underlying solid mesh. The initial adjustment of contact nodes and repositioning of solid element nodes due to mesh morphing are 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 IDs 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.

For general contact (InterType = GCN), RID1 and RID2 are section IDs associated with general contact surfaces instead of real constant IDs. If RINC = 0, the Option is performed between the two sections, RID1 and RID2. If RINC > 0, the Option is performed among all specified sections (RID1 to RID2 with increment of RINC).

intertype

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.

The following labels specify the type of contact interface:

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

  • "GCN" : Include general contact definitions only (not valid when Option = RESET or AUTO).

The following labels specify the type of contact pairs to be trimmed/unselected/auto-set (used only when Option = TRIM, UNSE, or AUTO, and only for pair-based contact definitions):

  • "ANY" : All types (default).

  • "MPC" : MPC-based contact pairs (KEYOPT(2) = 2).

  • "BOND" : Bonded contact pairs (KEYOPT(12) = 3, 5, 6).

  • "NOSP" : No separation contact pairs (KEYOPT(12) = 2, 4).

  • "INAC" : Inactive contact pairs (symmetric contact pairs for MPC contact or KEYOPT(8) = 2).

  • "TRlevel" : mming level (used only when Option = TRIM, UNSE, or MORPH):

  • "(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.

cgap

They are only valid when Option = ADJUST or MORPH. Control parameter for opening gap. Close the opening gap if the absolute value of the gap is smaller than the CGAP value. CGAP defaults to 0.25*PINB (where PINB is the pinball radius) for bonded and no-separation contact; otherwise it defaults to the value of real constant ICONT.

CPEN

They are only valid when Option = ADJUST or MORPH. Control parameter for initial penetration. Close the initial penetration if the absolute value of the penetration is smaller than the CPEN value. CPEN defaults to 0.25*PINB (where PINB is the pinball radius) for any type of interface behavior (either bonded or standard contact).

IOFF

They are only valid when Option = ADJUST or MORPH. Control parameter for initial adjustment. Input a positive value to adjust the contact nodes towards the target surface with a constant interference distance equal to IOFF. Input a negative value to adjust the contact node towards the target surface with a uniform gap distance equal to the absolute value of IOFF.

Notes

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.

For additional details, see the notes section at: https://www.mm.bme.hu/~gyebro/files/ans_help_v182/ans_cmd/Hlp_C_CNCHECK.html

On this page
Edit on GitHub