x-bracing

[JPAULI167]

L4x4x1/4 x-bracing with 4 kip axial load and 2 kip horizontal load. There is a single 7/8" dia A490 bolt connecting them in the middle. How do you check the design for that bolt?

 

[ToadJones]

2 kip load out-of-plane?

 

[JPAULI167]

nope, the 2 kip is in-plane

 

[slickdeals]

A bolt with combined shear and tension?
Use the provisions of Section J3.7 of the AISC manual.

 

[ToadJones]

well, I still don't follow the 2 kip load application...maybe provide a sketch.
However, if there are two continuous angles lapping each other and the bolt is just pinning them together, then the bolt is really doing just that, pinning the angles together and really will not see any load other than secondary forces resulting from deformation/ deflection of the angles.

 

[connectegr]

Bolt connecting in the middle? Where the braces cross in the center?

I don't think there should be any load at the intersection. Usually a fill plate with a single bolt. Use and OVS hole, finger-tight, and damage threads. The bolt will prevent out of plane buckling, but not resist any load.

http://www.FerrellEngineering.com

 

[ToadJones]

I agree with Connectegr

 

[ToadJones]

connectegr-
I have to give you credit....seems like you deal with nothing but the most agonizing part of structural engineering ...Connections.

 

[JPAULI167]

Thank you Toad and Connect as I agree with you both and your quick response is appreciated.

 

[dik]

The only other comment is... a 7/8" A490... good for a bunch.

Dik

 

[connectegr]

ToadJones
Thanks.

I never really had a choice. I am the son of an erector/fabricator. My dad started as a field engineer for CBI and later director of engineering for a large fabricator. From the time I could write, I was using a lettering guide. I worked on the drawing board while in high school and in the shop as a welder/fitter in college. Our company specializes in what we know best. I spend most of my day working out these field issues and design problems to keep production moving. I do love my job. I am also enjoying this forum. At least I am not the only one dealing with weird questions. I am certainly learning more than I am contributing.

http://www.FerrellEngineering.com

 

[ToadJones]

I just know from being involved in some complicated designs, mostly in the power industry, that connection design can be very difficult from a technical standpoint. Time spent on that part of the job can far exceed that used during superstructure analysis.

Kudos