SFCGEN

SFCGEN, option,P0, COMPC, CSYS, DOF, Wtfact, ICTY, ITTY, RID, RADIUS
Generates MPC surface-based constraints based on components.

PREP7: Meshing

option

Specifies the type of constraint to be generated.

**`1` or `FORCE`**	—	Force distributed constraint
**`2` or `RIGID`**	—	Rigid surface constraint.
**`3` or `Coupling`**	—	Coupling constraint.

P0

Pilot node number for a surface-based constraint.

COMPC

The name of the element component with Face ID (EFACE component(s) via the CMBLOCK command) to define the contact surface with CONTA174 and NODAL components, or the node number to generate CONTA175 as contact elements.

CSYS

The number of the coordinate system used to specify surface-based constraints in the local coordinate system.

DOF

The degrees of freedom of the surface-based constraints. Specify a six-digit value similar to KEYOPT(4) of the target element TARGE170.

Wtfact

Table name (input as %TableName%) of weighting factors for force-distributed constraints. See notes.

ICTY

Contact element type ID. If ICTY is not specified, the program selects the next available contact type ID number.

ITTY

Target element type ID. If ITTY is not specified, the program selects the next available contact type ID number.

RID

Unique real constant ID number. If RID is not specified, the program selects the next available real constant ID number.

RADIUS

Radius of influence range specified as the real constant PINB.

Notes

The SFCGEN creates surface-based multi-point constraints (MPC) that contain one pilot node, a target segment meshed with the target elements TARGE170, and a contact surface meshed with CONTA174 or CONTA175. The makeup of the constraint depends on how you specify COMPC:

If COMPC is element components with face ID (EFACE component(s) via the CMBLOCK command), the command generates contact surface elements CONTA174 on the faces of base elements.
If COMPC is a nodal component or node number, the command generates CONTA175 as contact elements.

If ITTY (target element type ID) and ICTY (contact element type ID) are specified, the appropriate and corresponding contact and target element key options must be set for the MPC surface based constraint. For more information, see Multipoint Constraints and Assemblies in the Contact Technology Guide.

You can specify user-defined weighting factors in tabular format (specify Wtfact as %Table Name% ) with node number as the primary variable. The program internally sets KEYOPT(7) = 2 on the target element (TARGE169 or TARGE170). By default, the program computes weighting factors automatically by summing the contact area of each contact node. When you set KEYOPT(7) = 1 on the target element (TARGE169 or TARGE170), the program uses a constant weighting factor of 1.0 for each contact node (similar to the default behavior of Wtfact on RBE3). For more information, see Surface-Based Constraints in the Contact Technology Guide.