Description
The SPCRD entry enforces time varying displacements and rotations on a rigid body. Constant displacements or rotations on a rigid body can be enforced using the SPCR entry.
In general, it is not recommended that you introduce an initial non-zero displacement at time zero. Instantaneous non-zero boundary conditions applied in an explicit dynamics analysis introduce very strong shocks into the model. If the magnitude of the displacement is large enough, the initial displacement can turn elements inside-out in the first time increment. Care should be taken to specify an appropriate amplitude via the TABLED1, TABLED2 or TABLEH options used to define the time-history for and SPCRD entry.
If grid points that belong to a rigid body have conflicting single-point constraints applied to them by an SPC entry or an SPC1 entry, this SPCRD option will override those values.
Format
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| SPCRD | SID | PID | C | D |
Example
| SPCRD | 2 | 4 | 246 | 1.E-3 |
| Field | Definition | Type | Default |
|---|---|---|---|
| SID | Identification number of single load set. | Integer > 0 | Required |
| PID | Property identification number of the property entry that uses the MATR1 entry. | Integer > 0 | Required |
| Ci | Component number of global coordinate. (Up to six unique digits may be placed in the field with no embedded blanks.) | 1 ≤ Integers ≤ 6 | Required |
| D | Enforced displacement for all coordinates of the rigid body reference node designated by PID and C. | Real or blank | 0.0 |
Remarks
- The LOAD entry will not combine an SPCRD entry with other loads.
- The SID on the SPCRD entry references either the material identification number, MID, on a MATR1 entry or the element identification number, EID, on an RBE2 entry.
- The constraints are applied to the reference node for the rigid body.