Geometric transformation, linear, P-Delta, corrotational

[IHK]

Hi,

I am trying to understand what exactly happens during the three types of transformations and how I could reproduce the results by hand (or with Excel) on a very simple model since I don't fully understand what it means.

Did someone already try this or knows some documentation where the three are explained in detail and we can see what exactly is happening when OpenSees applies them?

Thank you

Beginner user,