Eurocode 8 - chord rotation

[math4engz@gmail.com]

Dear All,
I am trying to understand the results under "Performance Criteria Checks" by comparing them to my hand calculations. My model contains two nodes and one cantilever column element. I am applying an axial and a horizontal load to the upper node and I am restraining the lower node. I run a static analysis (non-variable load). I calculated the total chord rotation capacity from Eq. (A.1) of EN 1998-3, but when I go to "Performance Criteria Checks" I find 4 values of the capacity for the performance criterion I have already pre-defined:
- End(A) - axis(2) --> value (doesn't matter the actual value)
- End(A) - axis(3) --> value
- End(B) - axis(2) --> value
- End(B) - axis(3) --> value

Now, first of all, which is End(A) and which is End(B)?
Secondly, why do I have 4 different values of the capacity when the column is square and with symmetric reinforcement? Finally, none of the values perfectly matches my hand calculated results, but maybe I made an error somewhere. Anyway, it would be helpful if you could answer my first two questions. Thanks!

[math4engz@gmail.com]

And one more thing:
why does the capacity depend on the applied horizontal load? Since the structure is a cantilever, the shear span should remain constant, right? For a small horizontal force (1 kN), the chord rotation capacity is like 10%, whereas for a reasonably large horizontal force the chord rotation capacity drops to 4%. Any idea?

[z.gronti]

Dear math4engz@gmail.com,

The End(A) and End(B) correspond to the start and end integration sections of the column correspondingly. The axis(2) and axis(3) correspond to the section's local axes.
You may find more information about the chord location calculations in Appendix H1 of SeismoStruct's User Manual.