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Selim Hocam, I think I am describing my problem wrong. I am trying define column elements that have different cross sectional dimensions and not aligned at the centroid of each cross section. Please see this example sketch I created in this dropbox link: https://www.dropbox.com/s/l75jdbop9lvjrhj/Col...

Selim Hocam, You mean I should shift the centroid of the fiber section and it should shift the element centroid? Just like this below? set shiftYDir [expr 20.0]; # inches set coverY [expr $HSec/2.0 - $shiftYDir]; set coverZ [expr $BSec/2.0]; patch quadr $IDconcU $nfZ $nfY -$coverY $coverZ -$coverY -...

Anybody knows how to do this? Selim Hocam, do you know?

Hi! I have a quick question. Is there a way to define a section or element that is offset from the center line of the adjacent element? For example, if a 15 foot column with a block-out consists of 20x40 cross section for 10 feet, 20x20 for 3 feet but flushed on the face of the 20x40 section, and 20...

What is the error message?
It should work with the original example!
There may be some other scripts, search for "material test opensees" in the forum or google. There is many ways that you can test the material, the link I gave above is just an example.

Baha

These may help you:

https://opensees.berkeley.edu/wiki/inde ... l_Material

https://opensees.berkeley.edu/wiki/inde ... Aggregator

And you may test your material using, e.g., https://opensees.berkeley.edu/OpenSees/ ... al/751.htm

Regards,
Baha

You need to look at the diff equation of the Bouc-Wen model on the reference documents at the bottom of the page on the link you sent. You can also test you material to see the effects different parameters; e.g., refer to https://opensees.berkeley.edu/OpenSees/manuals/usermanual/751.htm The definiti...

Hi, I am wondering if there is a way to orient a fiber cross section and rotate it for a 2D problem? For example if I defined a fiber cross section, such as one of these fiber sections: http://opensees.berkeley.edu/wiki/index.php/OpenSees_Example_9._Build_%26_Analyze_a_Section_Example Is there a way...

I wonder if there is a way to simply assign masses to line elements (just using mass/length) without needing to create many nodes and assigning concentrated/lumped masses to each node?

Sincerely Yours,
Baha

Hi, I have a quick question. Is there a problem with using initial strain (or stress) material and pushing it as displacement controlled? I created a RC simple supported beam (4 point beam) with concrete and steel as initial strain material. - For example, when I apply a loading two 10kips , I get a...

Hello there,
Is there any example of a pre-stressed beam modeled in OpenSees?
Regards,

Yeah, though FFT peaks are cumulative measurements of time history. But I have been thinking if there is a way to see the mode shapes (therefore force distributions) instantaneously as the system goes through transitioning modal coordinates since every little change in the stiffness due to inelastic...

Thank you for your reply. I am actually thinking it as earthquake forces experienced by the building right at that step while building is going through different periods, rather than its damage implication. It makes me think about the meaning of periods that "eigen" command give in each time step be...

Notwithstanding it is complicated, those eigen values should still be meaningful in terms of the frequency that the building experiences, right? The eigen values I get with the "eigen" are not negative during an analysis I ran. I wonder if this is just by luck all positive or not? Similarly I am get...

I have one more followup for the "eigen" or "nodeEigenvector" commands. How do those commands calculate eigen values and vectors when the stiffness negative or, e.g. in the unloading branch? Isn't there a complication of negative lambda values? I remember seeing in some posts that there may be negat...