GROUNDCHECK

Rigid Body Motion Grounding Check

Description: Perform grounding check analysis on the stiffness matrix to expose unintentional constraints by moving the model rigidly.

Format:

Examples:

GROUNDCHECK=YES

GROUNDCHECK(SET=(N), GRID=12, THRESH=1.-5, DATAREC=YES) = YES

Option	Definition	Type	Default
SET	Specifies at what point in the solution sequence to perform the rigid body motion grounding check. One of the characters variables: G Perform checks after stiffness matrix assembly before multipoint constraints are applied. N Perform checks after multipoint constraints are applied before single point constraints are applied. F Perform checks after single point constraints are applied before static condensation. A Perform checks after static condensation before decomposition. ALL Perform all checks.	Character	G
gid	Reference grid point for the calculation of the rigid body motion.	Integer > 0
etol	Maximum strain energy which passes the check.	Real ≥ 0.0	See Remark 1
DATAREC	Option for outputting grounding forces. One of the following character variables: YES or NO.	Character	NO
rtol	Percent tolerance for grounding force output when DATAREC=YES.	Real ≥ 0.0	10.0

Remarks:

1. The default THRESH value is computed by dividing the largest term in the stiffness matrix by 1.0E+10.
2. If DATAREC=YES, GROUNDCHECK forces will be output in the grid displacement coordinate system.