Moment Connection Under the Flange

[vmirat]

I need to design a moment frame using HSS10x10x1/2 columns and W12x16 beam. The problem: I can't have anything additional on the exterior face of the beam flanges.

Has anyone ever done a moment connection by using attachment plates on the interior face of the beam flange? See attached detail.

 

[MotorCity]

Your detail is possible, but it would need to be welded since you cannot have bolts protruding past the flanges. Would be easier to just full pen weld the beam flanges to the column

 

[dhengr]

Vmirat:
I’d put and end pl. on the WF beam and let it hang down 12-16" below the bot. of the beam, to be welded to one side of the 10x10 HSS col. I’d put two web stiffeners flg. to flg. in the beam, to match the location of the opposite side of the col. I’d put what appears to be a 10x10 bearing pl. on the bot. of the WF beam and weld the whole thing to the HSS as req’rd. With a little engineering imagination this should work to develop the moment cap’y. of the beam section.