HSS Column Axial Load Charts 1

[cap4000]

The typical Euler Stress KL/r is used for the development of the AISC Axial Load Tables. I have the AISC 1997 HSS Connections Manual and it has many different checks that must be performed on the HSS depending on the connection method selected. Tube Wall crippling and crushing under compression yielding is checked when using cap plates. Seems to me that the allowable axial load is highly dependent on the connection type used. Has anyone ever checked all the limit states for allowable axial load and compared those results with the connections capacity. Any tips will be greatly appreciated.

 

[271828]

The axial load in the tables is for member strength only. Connection limit states and combined bending and axial must be checked separately. I don't get the point of the comment--are you of the opinion that the phiPn tables should be adjusted for connections? I see no logic in that.

 

[cap4000]

271828

When you frame a typical beam for gravity loads to a WF column their is nothing to worry about with regards to the column flanges and the web. Simply look in the Axial Load Chart with a KL/r and you have your Allowable Load and therefore the column selection. With a HHS its similar however the beam connection design and the type of connection may change and increase the wall thickness of the tube mainly due to the HSS wall yielding, crippling and crushing. A big difference in the "approach" to a column selection as I see it. I believe the limit state checks for tubes started in the early 1990's. AISC no longer prints the 1997 HSS Connection Manual which had over 30 pages of errata. Its all now been combined into the latest Manual.

 

[twinnell]

Yes there are connection checks that have to be done for HSS sections. Design the member using the charts. Then design the connection and look at the appropriate checks. If the wall thickness needs to be increased, then pick a heavier member.