How to consider the rotational mass in linear elastic static analysis?

[marafini.f]

Good I am glad!
You are welcome.
Francesca

[pucho]

Dear Francesca thank you for your help. As I mentioned in the previous message, the model is correct for modal analysis; however, I am having some difficulties performing pushover analysis. The model represents a two-story confined masonry building and when I try to run a self-weight analysis in 10 steps, OpenSees stops in the last step. Could you please take a look at my file, I am attaching the error message and the STKO files.

Best regards,

Hernan

[marafini.f]

Hi pucho,

so in the model that you sent me, I do not see that error.
I noticed that you applied a physical property to this additional column, which is a distinct geometry connected with an interaction, but then did not apply any element property nor any condition to the interaction. I do not understand what is the purpose of that column nor the interaction.

That can give you a singularity that you do not see in the vertical analysis because you fixed the geometry at the base so it is still connected. Anyway, try to check this out and send me the model that yields that error.

Francesca

[pucho]

Thank you very much for the fast reply,
The purpose of the column is to consider the interaction between masonry (defined using shell elements). I am attaching the file with this error. Please take a look at it.

[admin]

Dear pucho,
I just had a quick look.
so if you erase your column and run the analysis no error occurs, so I think there is something wrong with how you defined them. I would suggest you draw your geometry separately and then move it in place after you created the interaction. Moreover, you need to check for instability, are you sure you gave enough DOFs property to avoid geometric singularities?
Let me know how it goes and if you need more help I will dedicate a bit more time to it!
Francesca

[pucho]

Thank you Francesca.

I will do as you say as for the drawing of the columns. Regarding the singularities, how can I check this?

In addition, I modified the model by changing the previous interactions by equal DOF constraints and the analysis was smooth with no convergence problems.

Best regards,

Hernan

[marafini.f]

The analysis was smooth because equalDOF is connecting all DOFs, so there is not free DOFs that can create a singularity. How are the columns connected with walls in reality? Is there a bonding layer or they are just adjacent?
To check if you are connecting enough DOFs you could start by connecting all DOFs in the zeroLength (assigning a material in all directions) and then scaling down, to understand what is the minimum number you need. But anyway I am not sure it is the right way to model this problem you want to study, tell me a bit more about it, what kind of result are you expecting in terms of the interaction between the column and the wall?

[pucho]

Dear Francesca, thank you for your help.
The columns in reality are built as shown in the attached picture.
I am trying to capture the interaction between masonry and confining concrete columns. I did as you recommended and verified that the columns represented by linear elements are connected with the shear elements representing the walls.
However, the convergence problems persist. Can you please provide other recommendations?

Best regards,

Hernan

[baovietgps]

I think need an extra layer of horizontal iron

[marafini.f]

Hi pucho,
can you attach the new model?