RBE1
Bulk Data Entry Defines a rigid body connected to an arbitrary number of grid points.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
RBE1 | EID | GN1 | CN1 | GN2 | CN2 | GN3 | CN3 | ||
GN4 | CN4 | GN5 | CN5 | GN6 | CN6 | ||||
"UM" | GM1 | CM1 | GM2 | CM2 | GM3 | CM3 | |||
GM4 | CM4 | GM5 | CM5 | etc. |
Example
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
RBE1 | 14 | 100 | 123456 | ||||||
UM | 101 | 123 | 102 | 123 |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
EID | Unique element
identification number. Must be unique. No default (Integer) |
|
GNi | Grid points at which
independent degrees-of-freedom for the element are assigned. No default (Integer or <PartName.number>) 6 |
|
CNi | Independent degrees-of-freedom in the global coordinate system for the rigid element at grid point(s) GNi. | |
UM | Indicates the start of the dependent degrees-of-freedom. | |
GMi | Grid points at which
dependent degrees-of-freedom for the element are assigned. No default (Integer or <PartName.number>) 6 |
|
CMi | Dependent
degrees-of-freedom in the global coordinate system for the rigid
elements at grid point(s) GMi. No default (Integers 1 through 6 with no embedded blanks) |
Comments
- The total number of components in CN1 to CN6 must equal six; furthermore, they must jointly be capable of representing and general rigid body motion of the element. The first continuation entry is not required if there are fewer than four GN points.
- The degree-of-freedom declared dependent on this entry may not be:
- A degree-of-freedom cannot be both independent and dependent for the same element. However, both independent and dependent components can exist at the same grid point.
- Rigid elements, unlike MPCs, may not be selected for use in individual subcases; they apply to all subcases.
- Rigid elements are ignored in heat transfer analysis.
- Supported local entries in specific parts can be referenced by the use of "fully-qualified references" on RBE1 entries in the model. A fully-qualified reference (PartName.number) is similar to the format of a numeric reference. PartName is the name of the part that contains the referenced local entry (part names are defined on the BEGIN Bulk Data Entry in the model). number is the identification number of a referenced local entry in the part PartName. See Parts and Instances in the User Guide for detailed information on the use of fully-qualified references.