Single Angle - Compression Members

[slickdeals]

AISC has a requirement that single angle members, if connected to opposite legs, should be designed for eccentricity. I believe this has been in the code for quite a long time.

However, I have also come across a paper by Dr. Thornton, with the following conclusion:

CONCLUSION
The examples given show that the eccentric effect of the
connections to opposite angle legs is very small except for
very short connections (L/g < 4), and can safely be ignored.
For short connections, consideration should be given to
eccentricity by performing the calculations outlined in this
note, or short connections should be avoided by keeping L/g
³ 4, approxmately.

Thoughts?

I also have another question:
It appears AISC allows eccentricity to be ignored in statically loaded connections, when the connection is to the same side of the member (single angle, single WT) etc. However, if a member has been designed to say 90% of the tensile/compressive strength, addition of a small moment will cause significant overstress. Blodgett's book suggests to design the WT for moment caused by this eccentricity.


It’s no trick to get the answers when you have all the data. The trick is to get the answers when you only have half the data and half that is wrong and you don’t know which half - LORD KELVIN

 

[ToadJones]

I hate to sound coy, but I just use the eccentrically loaded tables in the SCM.
There is also some design tables I have come across over the years for this design.
If the angle is connected on one leg, even if it is the same lege on both ends, I still use the "e" tables.
Single angle compression members aren't my favorite so I prefer to almost always use the "e".

 

[dik]

Slick:

 

[dik]

Slick

 

[dik]

The second one was too big to send...

Dik