RBE3 (Rigid Body Element, Form 3)

Interpolation Constraint Element

Description: Defines the motion at a reference grid point as the weighted average of the motions at a set of other grid points.

Format:

1	2	3	4	5	6	7	8	9	10
RBE3	EID		REFGRID	REFC	WT		G1	G2
	G3	G4	...

Example:

1	2	3	4	5	6	7	8	9	10
RBE3	EID		REFGRID	REFC	WT		G1	G2
	G3	G4	...

Field	Definition	Type	Default
EID	Element identification number.	Integer > 0	Required
REFGRID	Reference grid point identification number.	Integer > 0	Required
REFC	Component numbers at the reference grid point. (Up to six unique digits may be placed in the field with no embedded blanks.)	1 ≤ Integers ≤ 6	Required
WT	Weighting factor for components of motion at grid points Gi.	Real	Required
Gi	Grid points have weighting factor WT in the averaging equations.	Integer > 0	Required

Remarks:

1. Components REFC at grid points Gi must be able to react rigid body motion resulting from REFC.
2. Blank spaces may be left at the end of a Gi sequence.
3. By default, a dependent degree of freedom assigned by one element cannot be assigned dependent by another rigid element and cannot be additionally constrained (e.g., single-point constraint).
4. 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.
5. Rigid elements, unlike MPCs, are not selected through the Case Control Section.