Rigid diaphragm in a frame with joint2D elements

[evgin]

Hi

I was wondering how can I constrain the dof1 of the nodes in each floor in a frame where I use joint2D elements for joints ?

Since the central nodes are generated automatically by joint2D then when I use equalDOF command , it gets me a convergence error.

I use this for that purpose :

# start from 2nd floor

set cennodetag 200; # the cennodetag are the same is the tags of central nodes generated by joint2D


for {set i 2} {$i <= $Nnodesy } {incr i 1} {


for {set j 2} {$j <= [expr $Nnodesx] } {incr j 1} {


#constrain the dof 1 of all the nodes to node 1 in each floor

equalDOF [expr $cennodetag+1] [expr $cennodetag+$j] 1;


}
set cennodetag [expr $cennodetag+100];
}


Or using joint2D would automatically simulate rigid diaphragm in a 2D frame?

Thanks
Reza.

[fmk]

in a 2d frame you can add the constraint for the rigid diaphragm just be setting the horizontal translations to move together with an equalDOF command .. the rigidDiaphragm is only really needed for 3d case due to rotation of the floor.

[evgin]

Thanks , i think i asked my questions not quite properly . I meant exactly what u mentioned as it can be seen in the peace of code I have shared above .

However, i meant in order to set the horizontal translations, to move together using equalDOF since i have no joint node separately defined as those are generated through joint2D in each joint , then should I set these nodes ( central nodes generated through joint2D) to move together using equalDOF command ? I did so but i am getting convergence error .

Please advise.

[fmk]

if using the command you specify the 4 external nodes for the joints so you have 4 nodes to play with for the equallDOF command .. and joint2d does not set a rigid diaphragm, e.g. nodes 1 and 3 of differening joints for example can move different horizontal amounts