GCDEF, Option, SECT1, SECT2, MATID, REALID, SECT1END, SECT2END
Defines interface interactions between general contact
surfaces.
OptionOption to be performed.
(blank) | — | Retain the previous |
AUTO | — | Define auto asymmetric contact between
surfaces |
SYMM | — | Define symmetric contact between
surfaces |
ASYM | — | Define asymmetric contact with |
EXCL | — | Exclude contact
between surfaces |
DELETE | — | Remove the
given definition from the GCDEF table. Note that GCDEF,DELETE,ALL,ALL does not remove the entire GCDEF table; it merely removes any existing GCDEF,,ALL,ALL definitions, while leaving intact any existing GCDEF definitions that are more specific. To remove the entire GCDEF table, issue GCDEF,DELETE,TOTAL. It is good practice to list all definitions using GCDEF,LIST before and after a GCDEF,DELETE command. |
LIST | — | List stored GCDEF data entries. GCDEF,LIST lists all defined interactions.
GCDEF,LIST, |
TABLE | — | List interpreted general contact
definitions in tabular format. By default, rows/columns of the table that match neighboring rows/columns are compressed to simplify the table. Issue GCDEF,TABLE,TOTAL to list the entire GCDEF table without removal of duplicate rows and columns. |
TABLESOL | — | List a table showing actual interactions
considered during solution. This option is only
available after the SOLVE command.
The table shows MAT and REAL entries considered during the solution (actual contact may or may not have occurred). This is in contrast to GCDEF,TABLE, which shows the user specifications. For auto asymmetric contact, TABLESOL indicates which of the possible contact versus target surface combinations was considered. |
SECT1, SECT2Section numbers representing contact (SECT1) and target (SECT2) general contact surfaces (no defaults). (In
most cases, the actual determination of contact versus
target surfaces takes place during SOLVE.)
A node component name is also valid input for
SECT1 and SECT2.
The component name is not stored. Instead, the program loops through all
valid section IDs found in the component and creates
GCDEF entries for all possible SECT1/SECT2
combinations that result. These entries are reflected in the
Option = LIST and TABLE output. Section IDs
can be further controlled by adding an extension (_EDGE, _FACE, _VERT, _TOP,
or _BOT) to the end of the component name. See Specifying General Contact Interactions Between Nodal Components in the Contact Technology Guide for more
information.
The following labels are also valid input:
SELF | — | Self contact. |
ALL | — | All general contact sections IDs. |
ALL_EDGE | — | Section IDs of all CONTA177 general contact line elements (which may be on the edges of 3-D solid and shell base elements, or on beam base elements). |
ALL_FACE | — | Section IDs of all general contact elements on faces of solid or shell base elements (both top and bottom faces of shell elements). |
ALL_VERT | — | Section IDs of all CONTA175 general contact vertex elements (which may be on convex corners of solid and shell base elements, and on endpoints of beam base elements). |
ALL_TOP | — | Section IDs of all general contact elements on top faces of shell base elements, and faces of solid base elements. |
ALL_BOT | — | Section IDs of general contact elements on bottom faces of shell base elements, and faces of solid base elements. |
The ALL_ labels apply to all defined general contact element section IDs in the model without regard to the select status of the elements or attached nodes.
See SECT1/SECT2
Interactions for a description of how the various inputs for
SECT1 and SECT2
are interpreted.
MATIDMaterial ID number for general contact interaction
properties at the SECT1/SECT2 interface. If zero or blank, the previous setting of MATID for SECT1/SECT2 (if any) is retained.
As an example,
you could specify "always bonded" contact behavior at the interface
by setting MATID to 2 and issuing the command TB,INTER,2,,,ABOND.
The coefficient of friction MU is also defined by MATID. Since the default is MATID = 0, frictionless contact (MU = 0) is assumed by default.
REALIDReal constant ID number for general contact interaction
properties at the SECT1/SECT2 interface. If zero or blank, the previous setting of REALID for SECT1/SECT2 (if any) is retained.
As an example,
you could specify contact stiffness (FKN) = 10 at the interface by
setting REALID to 14 and issuing the command R,14,,,10.
SECT1END, SECT2ENDLast section number in the range. For Option= LIST, TABLE, or TABLESOL, data entries are
processed for contact section
numbers in the range from SECT1 to SECT1END, and target section numbers in the
range from SECT2 to SECT2END. SECT1END and
SECT2END are ignored for all
other Option labels.
GCDEF defines the interface interaction between
general contact surfaces identified by SECT1 and SECT2. GCDEF commands
are order independent in most cases.
GCDEF definitions should be issued after GCGEN. They are saved in the database and are written to and read from .CDB files.
See General Contact in the Contact Technology Guide for more information on the overall procedure to create general contact.
The most specific types of general contact definitions are those described below:
SECT1 = any valid general surface
section ID and SECT2 = any different valid
general surface section ID: Option, MATID, and REALID apply
to general surface interactions between SECT1 and SECT2. This is one of the most specific
types of general contact definitions and is never overridden. |
SECT1 = any valid general surface
section ID and SECT2 = SECT1: Option, MATID, and REALID apply to general surface
self contact interactions involving SECT1. This is one of the most specific types of general contact definitions
and is never overridden. |
The remaining general contact definition types can be overridden by the above two general contact definition types:
SECT1 = ALL and SECT2 = ALL: Option, MATID, and REALID apply to all general surface
interactions, except where overridden by a more specific GCDEF command. |
SECT1 = ALL and SECT2 = SELF or SECT1 = SELF and SECT2 = ALL: Option, MATID, and REALID apply
to all general surface self contact interactions, except where overridden
by a more specific GCDEF command. |
SECT1 = ALL and SECT2 = any valid general surface section ID: Option, MATID, and REALID apply to all general surface interactions that include SECT2, except where overridden by a more specific GCDEF command. |
SECT1 = any valid general surface
section ID and SECT2 = ALL: Option, MATID, and REALID apply to all general surface interactions that
include SECT1, except where overridden
by a more specific GCDEF command. |