Moment Connection 4

[Mbasi]

Hi All,

Is it a common detail for beam to column web moment connection to share bolts. I am concerned that the bolts will have to resists double the tension applied from each beam to column moment connection. In the image attached, the beams go into the web where the endplates share bolts.

 

[dik]

AISC's 'DG_39-End_Plate_Moment_Connections' is an excellent source and has many worked examples. I use them as a guide for my SMath programs.

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

-Dik

 

[ALK2415]

is it really considered as moment connection ???
check the following

 

[dik]

Yes... I've used these plated end connections for 50 years for plactic designed moment shear connections at the cantilever. They work very well and are very cost effective. End plates are typically 3/4 or thicker to be stiff enough and to reduce any prying action. That the criteria I use for thickness.

From a recent project; This was used for a simple span beam splice at mid span. They needed to cut the beam in half to install in an existing structure. I usually like splicing at 1/3 point, but client wanted it at mid span:

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

-Dik

 

[lexpatrie]

I mean moment into the column. Like a moment connection in a bent frame, for example. You don't seem to be trying to do that. This is more like a beam splice that's interrupted by a column web.

That figure where it's strong axis is irrelevant to this situation, too.

Mbasi, if your column doesn't project above the floor, why don't you extend one of the beams over the top of it and connect to the other beam on the far side? If they're being that restrictive on the metal is there no deck or floor here? If that's the case couldn't you drop the beam 1/2" for a top plate/welded moment connection?

 

[dik]

Moment into the web, or moment into the flange... add a couple of stiffeners and it's done the same way. No difference. You can bolt the stiffened end plate to a flange just as easy as you can bolt it to another stiffened end plate. Add a couple of stiffeners to the column web-flange, and done like a dinner. If your endplate cannot extend above the beam flange, then use a bevel weld at the top flange. On the above example detail, that was what the fabricator wanted to do.

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

-Dik

 

[Mbasi]

The end plate definitely works as a moment connection. It's very unusual for Engineers to design a beam to column connection with a moment in the minor axis of the column. I agree, fabricators favour different options. You probably don't need column stiffeners if beams are fixed to the Web on both sides. The end plates are min 15mm thk and the Column is 203x86 UC with web thickness of 12mm and max moment of 75kNm from each beam

 

[dik]

For end plate thickness, I generally use the minimum thickness required to prevent prying action. I didn't know there was a minimum. More likely, you want to transfer the moment through the column to a beam, or cantilever on the other side.

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

-Dik

 

[Mbasi]

@lexpatrie unfortunately I am only commissioned to design for the steel connections as the steel frame was designed by another engineering firm

 

[dik]

If a frame and moments may be +ve or -ve, then the bolt pattern should be symmetrical, not as shown. The image is for moment in one direction only. Similar problem and solution, just a different detail.

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

-Dik

 

[JoshPlumSE]

What Dik said. These are just bolted, unstiffened, end plate connections. There is a whole AISC design guide (actually multiple) that covers them. A lot of good testing and research out of Virginia Tech too.

For what it's worth, the use of these connections to resist SEISMIC forces is more debatable. But, for gravity and wind loads, they are very commonly used.