How to model an element with a non diagonal stiffness matrix

Hello,

I would like to know how to model an element with a non-diagonal stiffness matrix in SOFISTIK. The use case is to model different kind of piers (steel, masonry, concrete) in order to simplify my SOFISTIK model.

I found in the Sofimsha module, the possibility to create the element “ADDM” in which you can input a stiffness matrix with the item “STIF”. It seems to be what I am looking for.


However, I do not understand how the syntax works for the item “STIF” of “ADDM”. I didn’t find how to use ADDM in the Teddy files examples for the Sofimsha module.
Could you please give me an example of how to define “ADDM” with a non-diagonal stiffness matrix “STIF” so I can implement an “ADDM” element in my own model ? I specify that my coordinates are in 3D (x,y,z).

Finally, is there another way to model an element with a non diagonal stiffness matrix in SOFISTIK ?

Thank you.

Attached you find a little example. Look into comments within the dat-file and results in Resultsviewer.

Best regards,
Jost

2024_example.dat (6.7 KB)
2024_example.gra (1.2 KB)
2024_example.results (2.9 KB)

Thank you.