inelastic parameters for rotational springs

[papaloo]

Hi dear vesna...
I'd asked you a question about my model which has a rotational spring.The subject of that question was "rotational springs".
As you advised me,I applied another ground motion to my model and changed Fy,b.
Again,I found out that the results aren't being changed by changing Fy,b.
As you know,a rotational spring has some parameters for inelastic range: My(yielding moment) and K'(post-yielding stiffness of rotational spring).
Could you please show me a command which clearly helps me defining a rotational spring with above mentioned parameters?
Thanks a lot.
Mohsen

[vesna]

One such material would be Steel01. It defines material by yield strength (strees), elastic stifness and post-yield stiffness.