Beam to HSS moment Connection

[STEVE97]

I am running into problems with designing beams to HSS columns. The engineer of record is requiring a moment frame design on were we need to design for the full moment capcity of the beam and use cut flage plate around the column. I am getting a huge required gross area for the tensile plate. It is my understanding that that area needs to remain constant from one side of the column to the other (beams on both side of the column). For this to be done 1/2 of the area needs to be provided on both sides of the column. I am finding it hard to find any references that address these connections. Does anyone have any ideas? The engineer requires the cut plates to be extended past the column and then a full penetration weld to the flanges of the beam. He also requires that the shear plate be extended to the flange plates and welded to remove any eccentricity from the shear connection and put that force into the flange plates. This connection does not seem typical and or economical and in all honesty does not make much sense to me. We have proposed that they use wide flange columns to ease the design of the moment connections and have it be more economical for the fabricator but they declined. Does anyone have any suggestions on how to proceed since I am stuck. Also there are conditions were he has two different depth beams coming onto the column. I told him that there would be a huge shear force in the column due to the opposing moments so he returned with a wacky detail that is non standard and ridiculous. Wouldnt it make more sense to use WF columns instead? Also what kind a forces do I need to check in the HSS column for this condition?

 

[csd72]

The AISC 'Hollow Structural sections Connections manual' adresses this type of detail.

It is a little black book.

 

[DaveAtkins]

What I have done in the past is cut the tube column into sections and weld through plates between the sections. A little unusual, perhaps, but not unheard of.

DaveAtkins

 

[COEngineeer]

I concur with Dave Atkins. Just cut the HSS at the bottom of the flange, weld plate, HSS same length as the web of the beam, weld plate, then continue the HSS again. It is hard but that is the only way.

Never, but never question engineer's judgement

 

[structuresguy]

Definitely get a copy of the Hollow connections manual. It contains everything (or almost) you need to know to design the moment connection.

We have used the continuity plate type moment conenction many times with HSS columns. Even at 4 sided moment connections. The fabrication and fit-up of the plate can be tricky (especially if not using computerized plate cutter), but it works well.

I have never used (or seen used) DAveAtkins idea, but it sounds like a workable solution as well.