This command is used to construct a number of Multi-Point Constraint (MP_Constraint) objects. These objects will constrain certain degrees-of-freedom at the listed constrained nodes to move as if in a rigid plane with the retained node.
|rigidDiaphragm $perpDirn $rNodeTag $cNodeTag1 $cNodeTag2 ...|
|$perpDirn||direction perpendicular to the rigid plane (i.e. direction 3 corresponds to the 1-2 plane)|
|$rNodeTag||integer tag identifying the retained node|
|$cNodeTag1 $cNodeTag2 ...||integer tags identifying the constrained nodes|
NOTE: The constraint object is constructed assuming small rotations.
NOTE: The rigidDiaphragm command works only for problems in three dimensions with six-degrees-of-freedom at the nodes (ndf = 6).
rigidDiaphragm 2 2 4 5 6; constrain nodes 4,5,6 to move as if in the same x-z plane as node 2.
Code Developed by: fmk