Remove soil layer

[thanh2611]

Hi,
My name is Thanh. I am trying to replicate this example in STKO. https://opensees.berkeley.edu/wiki/inde ... _Pile_Wall.

My question is how can I remove the soil layers like in this example.

Thank you so much

[STKO Team]

Dear Thanh,

Now you can remove elements as they did in the official opensees example, i.e. by element ID (this can be done in STKO using a custom script). However this is neither efficient nor general, and requires a good knowledge of TCL.

We are currently implementing a feature (a new AnalysisStep call "removeSubset") that will let you remove a subset of a geometry using different rules:

• Plain (the entire selectionSet will be removed when you issue the command)
• FunctionOfTimeAndSpace (elements and nodes will be removed as function of their spatial coordinate and time)
• FunctionOfElementResult
• FunctionOfNodalResult

This will be ready by the next week. I will inform you here when the new update will be available

[thanh2611]

Thank you so much

[thanh2611]

Dear STKO team,

I only knew to add tcl script to STKO in the analysis step. Therefore, I want to ask which feature can I implement tcl script in?

[STKO Team]

Dear than,
As I said, at the moment you can do it via the CustomCommand (TCL Script).

Attached you can find a (zipped) SCD file where I use the TCL custom command to remove elements and nodes as a function of space and time.

However there are some subtle issues with this approach (that's why we are implementing it in a more robust way directly inside the Python interface of STKO):

• the UMFPack solver does not work when you remove objects (I used the SuperLU for this)
• If you use the Penalty method, you need to remove all sp and mp constraints for every node that you remove (see my scripts)
• You cannot apply point loads on nodes that will be removed

Have a look at this sample file and let me know if everything is clear.

[thanh2611]

Thank you so much