The OpenSees Community

It is basically depends what kind of support you want chose. If you try a beam column element, then simply fix the bottom node.

One solution, you can use wide column and aggregate shear property. The other solution, you can try brick elements. But I recommend the first one.

Hope that helps,
Erol

Thanks alot,

You were right, version problem.

Hey Silvia, thanks for looking. this is really smt that I have to solve quickly. Because I modeled 19-story building in 3D and have problem with eigen. I did so many models before but never get the problem like that. I added the code for you, actually it is the same as Example5.1 I just seperated my...

Has anyone tried eigen analysis in 3D frame after peforming gravity analysis. I used example5.1 and do gravity analysis then I tried eigen, but eigen solver crashes. without gravity it works fine. I never get the same problem in 2D. I will apprecaite any comments for eigen analysis in 3D following g...

Try to load into Matlab, it would look better.

otherwise you may want to change to code and re-compile again.
hope that helps

eigen(# of modes)

Did you try zero-length element?

Hope that one helps, c++ code is as follows The class added under Globals for nodeeigen comand is: int nodeEigen(ClientData clientData, Tcl_Interp *interp, int argc, TCL_Char **argv) { if (argc < 3) { opserr << "WARNING want - nodeEigen nodeTag? dof?\n"; return TCL_ERROR; } int tag, dof; i...

For MPF computation, compute [story mass x eigen vector at the master joint] at each story and sum them up. It will be the modal participation factor. I did some changes in the code to get directly the eigen vectors at certain node number, I wrote a command for that [nodeEigen "nodenumber"...

Why dont you record the displacement with their time step at every node you want, then with simple script in matlab you can compute the displacement difference bw each node at each time step.

E. Kalkan

You should be getting three outputs

[time] [axial def] [curvature]

Erol Kalkan

My suggestion for question 2 is that:

Record all the forces at the bottom of the first story columns in the direction of loading, sum them up at each time step of the pushover analysis. That wil give you the total base shear for each time step.

Hi Frank,

Thanks for the reply,
Yes I want to combine the states, I know that they are nonlinear. We are working some approximate methods. So is it possible to add the states.
Thanks

Hello, My question is as follows, any help will be really appreciated. I need to perform seperate analyses on a model at each single step (it is like quasi-static analysis), but at each analysis case I need to save the state of analysis. Then starting to the next step I have to combine the states fr...