rigidDiaphragm Command

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Paolo
Posts: 12
Joined: Tue Feb 21, 2006 9:01 am
Location: Italy Bologna

rigidDiaphragm Command

Post by Paolo »

Hello!
I’m studying a simple Three-Dimensional Rigid Frame, similar to example 5 of “Open Sees Examples Primer”.
As in example I used
rigidDiaphragm 3 9 5 6 7 8
fix 9 0 0 1 1 1 0
and in this way dynamic analysis run.
If I cancel
fix 9 0 0 1 1 1 0
the analysis fail.
Do you know why?
Is it possible to permit the Diaphragm to move free?
Thank you for the attention.
Best regards.
fmk
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Post by fmk »

if it is failing you obviously don't have enough constraints .. remember that if you are using a dummy node for the master node, the dof not involved in the constraint must be fixed .. in the Example5.1.tcl 9 is a master node, it is not connected to any elements, it is just placed at the center of mass .. the fix 9 0 0 1 1 1 0 provide the fixity needed in the DZ, RX and RY directions.
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