when leaning column is necessary?

[ToBeLignos]

Hi everybody!

when it's necessary to consider P-delta effects by using a leaning column?

if the frame is a 2d peripheral frame withdrawn from a 3d structure, is it necessary to define leaning columns?

Does "Being a peripheral or middle frame" make any difference for considering or not considering leaning columns?

[ToBeLignos]

I have heard that if the frame is peripheral then leaning columns should be considered. is this true? why?

[vesna]

Leaning column can be added to the 2D model of a frame to capture the effect that the gravity system has on lateral-load resisting frame. It does not matter if the frame is peripheral or middle.

[fmk]

you need to consider a leaning column if loads carried by gravity columns (those gravity loads not carried directly by frame) are significant. if a peripheral frame, each frame is only going to take half of the rest of the loads not added to the frame directcly.

for small buildings this is typically a waste of time as load is not big enough to have any effect.