Column Design for Axial Load and Moment

[aswierski]

Does anyone have any good references on column design for axial load + moment? Say I have a 20' tall column with an allowable axial load of 20 kips. Say there is a moment of 5 foot-kips at the base plate. What would one have to take into account? I have AISC's latest errata of their Design Guide 1, but that isn't updated for Allowable Strength Design (ASD05).

 

[ishvaaag]

You use beamcolum (column with moments) equations in books or codes to resolve this. Chapter H of the LRFD code is a sample of such.

If you want to refer to ASD procedures, then (if allowed by the standing regulations) use ASD design, it is still chapter H of the AISC's ASD 1989 edition.

You can find nice exlanation of why and how in Gaylord, Gaylord and Stallmeyer's book

Design of Steel Structures.

 

[asixth]

Salmon and Johnson Chapter 12 has a section on combined compression and bending.

Any steel designers handbook will step you through the process, combined compression and bending is very common in design. You will need to calculate a reduced compression capacity depending on how close to moment capacity your section is.

If your column is a unrestrained free cantilever, you will need to calculate the effective length of your column. I would take 2.2*20'.