rigidDiaphragm

[babibibak]

Hi silvia,
i have modeled a 1 story building which has one bay in each direction.I want to make diaphragm rigid. I create a point in the center of mass and use rigidDiaphragm command to joint all other nodes to that point.
like :
rigidDiaphragm 3 105 101 102 103 104

i get different results when i use equalDOF command
like :
equalDOF 105 101 1 2 3 4 5 6
equalDOF 105 102 1 2 3 4 5 6
equalDOF 105 103 1 2 3 4 5 6
equalDOF 105 104 1 2 3 4 5 6

I can not understand their difference.
which one should i use to create a rigid diaphragm.

[silvia]

the rigid diaphragm only constrainsts certain degrees of freedom.
equaling both displacements and rotations does not allow the diaphgraphm to rotate.