Rigid Bar
Description: Defines a rigid bar with six degrees of freedom at each end.
Format:
Example:
| Field | Definition | Type | Default |
|---|---|---|---|
| EID | Element identification number. | Integer > 0 | Required |
| GA, GB | Grid point identification number of connection points. | Integer > 0 | Required |
| CNA, CNB | Component numbers of independent degrees of freedom in the global coordinate system for the element at grid points GA and GB. (Up to six unique digits may be placed in the field with no embedded blanks.) | 1 ≤ Integers ≤ 6 or blank | See Remark 1 |
| CMA, CMB | Component numbers of dependent degrees of freedom in the global coordinate system assigned by the element at grid points GA and GB. (Up to six unique digits may be placed in the field with no embedded blanks.) | 1 ≤ Integers ≤ 6 or blank | See Remark 2 and 3 |
Remarks:
- The total number of components in CNA and CNB must equal six; for example, CNA = 1235, CNB = 34. Furthermore, they must jointly be capable of representing any general rigid body motion of the element.
- If both CMA and CMB are zero or blank, all of the degrees of freedom not in CNA and CNB will be made dependent.
- The dependent degrees of freedom specified on this entry may not be additionally constrained by other rigid elements or single-point constraints.
- Degrees of freedom declared to be independent by one rigid body element can be made dependent by another rigid body element or by a multipoint constraint.
- Rigid elements, unlike MPCs, are not selected through the Case Control Section.
- Forces of multipoint constraint may be recovered with the MPCFORCES Case Control command.