# GRAV

Bulk Data Entry Defines the gravity vectors for use in determining gravity loading for the static structural model. It can also be used to define the EXCITEID field (Amplitude "A") of dynamic loads in RLOAD1, RLOAD2, TLOAD1, TLOAD2 and NLOAD1 Bulk Data Entries for dynamic solution sequences.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
GRAV SID CID G N1 N2 N3 MB

## Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
GRAV 47 3 32.2 0.0 0.0 -1.0

## Definitions

Field Contents SI Unit Example
SID Set identification number.

No default (Integer > 0)

CID Coordinate system identification number. A CID of zero references the basic coordinate system.
0 (Default)
References the basic coordinate system.

(Integer ≥ 0)

G Gravity vector scale factor.

(Real ≠ 0.0)

N1,N2,N3 Gravity vector components.

No default (Real; at least one non-zero component)

MB Specifies the Bulk Data section in which CID is defined.
This entry is applicable only for partitioned superelements. 5
-1
The coordinate system is defined in the main Bulk Data section.
0 (Default)
The coordinate system is defined in the Bulk Data section of the partitioned superelement.

(Integer ≥ -1)

$\stackrel{\to }{g}=G*\left({\stackrel{\to }{N}}_{1},{\stackrel{\to }{N}}_{2},{\stackrel{\to }{N}}_{3}\right)$
The direction of $\stackrel{\to }{g}$ is the direction of free fall. ${\stackrel{\to }{N}}_{1}$ , ${\stackrel{\to }{N}}_{2}$ , and ${\stackrel{\to }{N}}_{3}$ are defined in the coordinate system CID.