Unexpected result in Cyclic analysis of shear wall

[MitalChovatiya73]

Respected STKO Team,
I have watched webinar on RC Shear wall with frame on youtube ( Link: https://www.youtube.com/watch?v=MdFtp82SKrY&t=2119s) and followed each step but could not get the result of cyclic analysis. I only got result of vertical analysis(stage 1). I am using STKO 1.1.5 version and Opensees compiled by Prof. Nikola Tarque. I do not know the required changes to be done for updated version at this point of time.

(Update: I have unchecked wipe analysis command as suggested in other query and cyclic analysis started but failing to converge. I reduced increment up to 1e-10 but still could not converge it.)

Please guide me through this. I have attached .scd file also here. Any suggestions would be helpful.
Thank you.

[marafini.f]

Dear MitalChovatiya73,

In the model you provided the total duration of the analysis is 0, therefore the second stage will not be initialized.
You should make sure that the duration and number of increments of your analysis are consistent with the timeseries defined.

Let us know if you have any more problems.
Francesca

[MitalChovatiya73]

Respected Marafini.f,
I have changed the duration as suggested by you and it worked without any error.
Thank you so much for your quick response and valuable suggestion.

[MitalChovatiya73]

Respected STKO Team,
As I have mentioned that i had followed all the steps discussed in webinar but I am not getting approximate result. I have tried to change properties of concrete ( TC3D ) by following one research paper attached below but still could not get the result as I got from experiment. Can anyone please suggest the changes that I should look in to get the result? I also attached the plot that i got from STKO ( orange line is the STKO result and blue line is from experiment. )
Thank you so much in advance.

[STKO Team]

You should not change the material parameters matching those of a random article. You need to put values described in the experimental test you are trying to simulate.
If you share the details of your experimental test we can have a look

[MitalChovatiya73]

Respected STKO Team,
I have attached concrete test data ( 3 cubes ) which I got from compression testing machine. It is hard to extract information since data is not in form of stress-strain curve.
In addition, the paper I followed gave a simple equation to get stress-strain curve and also fracture energy and crushing energy with input of mesh size and mean compressive strength.
Kindly check the previous post if one wants to look for .scd file of the model.
Attachment:
Concrete cube test data

[STKO Team]

I had a look at those files. The give enough information to get the values for the DamageTC3D. However I think that an error in the fracture energies is not the main reason for that mismatch. Your numerical model is givin almost twice the experimental strength.

Even when the concrete fails, you can clearly see that also the rebars are giving a resistance (in the last parts of your cycles) that is almost twice.

I suspect that there is something wrong in your model, or in the boundary conditions.
Try to find out if there are differences between the experimental setup and your model, in terms of dimensions, or boundary conditons.

If you cannot find it, post some details about the experimental setup

[MitalChovatiya73]

Respected STKO Team,
I had changed model little bit to avoid over congestion of rebar near joints and get little closer result as attached below. But, strength during initial cycles are too much more than what I got from experiments. As STKO team suggested, I have attached experimental setup and cross section of shear wall ( without boundary element ). During test, shear wall detached from base block after few cycle and acted as pinned at bottom. I have taken equivalent area of wall to model it as a layered shell. Modified STKO model is also attached here.
Please have a look. Any suggestion would be great and thank you so much for timely response and valuable suggestions.

[STKO Team]

As you can see from the picture of the experimental test,
it looks like the wall is not well anchored to the bottom beam.
The failure pattern seems like that of a rocking mechanism.
The panel itself seems not to show any damage pattern.
Furthermore it looks like in the experimental test there is no rotation fixed at the top.
I suggest you to review the experimental test and make sure the boundary conditions are correct