CONNECT
Bulk Data Entry Define equivalence for degrees of freedom of grid points of two sections of the same model (Format 2) or different parts in a Parts and Instances Model (Format 1) within a specified tolerance.
The tolerance is defined as the maximum distance between two grid points within which equivalence is allowed. Two formats can be used to either select all grid points or a SET of grid points for equivalence.
Format 1 (Parts and Instances)
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| CONNECT | ID | name_a | name_b | tol | GSID |
Example
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| CONNECT | 12 | Cyl_Head | Gaskt | 0.01 |
Format 2 (General)
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| CONNECT | ID | tol | GSID |
Example
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| CONNECT | 12 | Cyl_Head | Gaskt | 0.01 |
Definitions
| Field | Contents | SI Unit Example |
|---|---|---|
| ID | Identification number of
the CONNECT Bulk Data Entry. No default (Integer > 0) |
|
| name_a | Name of a part selected
for equivalencing. Part "name_a" is the reference
part. All grid points in part "name_a" are
considered during the search; if OptiStruct finds grid points in part
"name_b" within the specified maximum
distance (tol), then such grid point pairs are
equivalent. No default (Character String) |
|
| name_b | Name of a part selected
for equivalencing. All grid points in part
"name_a" are considered during the search; if
OptiStruct finds grid points in part
"name_b" within the specified maximum
distance (tol), then such grid point pairs are
equivalent. No default (Character String) |
|
| tol | Specifies the numeric
value defining the maximum distance between two grid points to allow
equivalence. All grid points in part "name_a" are
considered during the search; if OptiStruct finds grid points in part
"name_b" within the specified maximum
distance (tol), then such grid point pairs are
equivalent. No default (Real > 0.0) |
|
| GSID | Optional
GRID SET ID. The grid point locations are
used to restrict the search for matching nodes. These grids do not
need to belong to either part "name_a" or part
"name_b". Default = Blank (Integer > 0) |
| Field | Contents | SI Unit Example |
|---|---|---|
| ID | Identification number of the CONNECT Bulk Data
Entry. No default (Integer > 0) |
|
| tol | Specifies the numeric value defining the maximum distance between
two grid points to allow equivalence. All grid points specified via
the GSID field are considered during the search;
if OptiStruct finds grid points within
the specified maximum distance (tol) of each
other, then such grid point pairs are equivalenced. OptiStruct considers element connectivity and
only equivalences grids within the specified tolerance that are not
structurally connected to each other. No default (Real > 0.0) |
|
| GSID | GRID SET ID. The grid point locations are used
to restrict the search for matching nodes. These grids do not need
to belong to the model. No default (Integer > 0) |
Comments: Parts and Instances
- Parts can be connected in two different ways, using the CONNECT entry or by using rigid elements. The RELOC and INSTNCE entries can be used to position the part appropriately within the full model and the CONNECT entry or rigid elements can be used to connect (equivalence) grid points of one part to the other.
- If the optional GSID argument is used, grid points in this set can be specified anywhere in the model, it is not mandatory for a grid point ID to belong to a specific part. Equivalencing takes place between any matching grids in both parts if they coincide with the location of any grid in the SET.
- Searches defined by this entry are performed after all parts are located at their final positions.
- If there are multiple grid points at the same location in any of the parts, CONNECT will only select one of them. It is usually a modeling error, unless such grid points are connected explicitly with Rigid Elements or MPC's.
Comments: General
- CONNECT entries can be used in a non-Parts and Instances model using Format 2. The GSID field is mandatory in such cases.
- The GMATCH entry can be used for similar functionality as CONNECT when the connection is required between two sets of grid points separated by a large distance (comparable or greater than the average element size).