Gusset Connection Eccentricity Problem 9

[dik]

I have a new project to design bracing for an existing building. The force in the bracing is Cf = Tf = 103K... big forces!

The problem is that the gusset will be secured at the centroid of the resisting beams and columns because there is an existing masonry wall located to the centerline of the connection. The EOR want me to design the connection for an HSS 10x4x0.5 (located at the face of the wall), welding the HSS to the face of the gusset, creating an eccentricity of 2" (from the HSS) + half the thickness of the gusset.

I've designed it using elastic combined stresses, based on a Whitmore width for compression. If it weren't for the compressive load, I'd have used the plastic section. I'm looking for some comments how others would design this for the eccentricity. I've suggested going to plate that is roughly 1"x12", in lieu of the HSS, to minimise eccentricity or possibly using the existing masonry wall for lateral forces.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[Ralph Pullinger]

Ideally - when using IDEA StatiCa you should start with the correctly applied forces and that also includes moments. In doing so the applied forces should be at their correct eccentricity. We have some scope to adjust in IDEA but generally we rely on good analysis results. The offset mentioned above depends on where the node of the connection has been defined. We can also adjust the location of action to go through the bolts which results in some internal re-calculation. If you would like us to take a look at this please let me know...

 

[dik]

Thanks for the very kind offer, but the problem has been resolved with a couple of caveats for the EOR to confirm and/or resolve. I've not encountered an eccentricity of that magnitude with forces of that magnitude. It ran up a couple of red flags. I used this forum to see how other engineers would approach it. The response was as I was hoping for.

The program seems to have an incredible capability and if I had numerous connections of that sort of complexity, I would seriously look into picking up a license. This is the first time I've encountered that type of requirement in 50 years of practice. Again, thanks.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik