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I am interested in applying the confinement of concrete according to CEB Model Code 1990 §3,5,2,1. According to the corresponding figure (Fig 3,5,4), concrete in tension contributes to the confining pressure in addition to confinement provided by the hoops. Consequently, the confining pressure is di...

http://opensees.berkeley.edu/wiki/index.php/GetNodeTags
I found this command in the command manual but there's no desciption. Does this mean that the command isn't available or has been removed?

On account of this topic, I would like to ask the reason for customarily assigning large values of torsional stiffness when modelling 3D buildings (like the example you posted above), instead of the actual stiffness calculated using the equations of engineering mechanics.

Instead of automatic e-mails to users, you could create a change log page, similar to the log page of the software: http://opensees.berkeley.edu/OpenSees/changeLog.php I think this would be easier to create and more informative, since all changed will be listed together.

Sorry, I found the answer elsewhere and forgot to update the topic. Add the command "pause" in a new line in the end:
echo off
cls
echo Starting OpenSees..
echo off
location_of_OpenSEES\openSees.exe location_of_your_model\yourModel.tcl
pause

An element is effectively rigid, if the results from analyses with different E (eg. 1000E & 10000E) do not vary significantly. Usually, E=1000*Ec would be enough.

Out of curiosity, is the element documented? I can't find it in the element list in the command manual: http://opensees.berkeley.edu/wiki/index ... nt_Command

By the sound of it, the slaveNodeTag argument accepts only variables and cannot discriminate the elements of a given list. The only solution that I can think of right now is to greadually construct the diaphragm, using multiple rigidDiaphragm commands. Put the command within a loop and use the linde...

I am not familiar with the rigidDiaphragm command, but this looks like a tcl-scripting error. If I understand correctly, the programme tries to implement a command defined by string "0 1 2 ....". Since there's no such command, an error is encountered. You can either try to remove the brack...

I think that you mean the total shear force of every column of a storey. I'm not sure if such a recorder is available, but you can you can calculate yourself the total shear force at the post-processing phase (eg. using matlab).

I suggest that you should study the following presentation concerining the differences between these two elements. http://opensees.berkeley.edu/wiki/index.php/Discovering_OpenSees_--_Force-based_Element_vs._Displacement-based_Element In general, displacement-based elements require a more detailed me...

Above all, you 'll have to change the geometric Transformation to PDelta http://opensees.berkeley.edu/wiki/index ... sformation (I'm guessing you're using Linear).

the gets command reads only a line of data every time http://www.tcl.tk/man/tcl8.5/TclCmd/gets.htm
try the read command, or use a loop to read every line

In order to assign damping values to 3 or more vibration modes, you have to use Caughey damping, but I do not know if such an option is available in opensees.

Have you specified a unique material tag?