Multi Point Constraint
Description: Defines a multipoint constraint equation of the form
where uj represents global degree of freedom Cj at grid point Gj.
Format:
Example:
| Field | Definition | Type | Default |
|---|---|---|---|
| SID | Set identification number. | Integer > 0 | Required |
| Gj | Grid point identification number. | Integer > 0 | Required |
| Cj | Component number of global coordinate (any one of six unique digits may be placed in the field). | 0 ≤ Integer ≤ 6 | Required |
| Aj | Coefficient. | Real or blank | 0.0; except A1 must be nonzero |
Remarks:
- Multipoint constraint sets must be selected with the Case Control command MPC = SID.
- The first degree of freedom (G1, C1) in the sequence is defined to be the dependent degree of freedom. By default, a dependent degree of freedom assigned by one MPC entry cannot be assigned dependent by another MPC entry or rigid element and cannot be additionally constrained (e.g., single-point constraint). If this behavior is desired, use PARAM, AUTOFIXRIGIDSPC which when set to ON will allow the constraint of dependent degrees of freedom. (See Section 5, Parameters, for more information on AUTOFIXRIGIDSPC.)
- Forces of multipoint constraint may be recovered with the MPCFORCES Case Control command.