P-M interaction and considering deterioration in column

[afakhimi]

Hi
In steel frame:
for IDA analyses in collapse assessment, i must consider deterioration in my model.
But for modeling my columns, If I use concentrated plasticity then I don’t consider P-M interaction and
if I use distributed plasticity then I don’t deterioration.
if I don’t want to use distributed plasticity model for my columns(fiber) so if I use concentrated hinge without consideration of P-M interaction how much approximate occur in my IDA analysis? and how important to consider P-M interaction in IDA analysis.
thanks a lot.

[afakhimi]

please help me

[vesna]

It depends on how strong P-M interaction is. If you have high axial forces the interaction may be strong and it would be smart to account for it in your model.

[afakhimi]

Hi
Thank you, vesna.
How do I know?
I work on mass irregular structures in height.
P-M interaction is effective for IDA analysis and For my 2D-frame ?

[vesna]

Look at the axial load ratio (P/Ag/fc') of your elements. If smaller than 0.1 the interaction is weak.

[afakhimi]

thank you
and for steel frame (P/A <0.1) ??