Fully Welded Beam to Column Web Connection 1

[peru4444]

I am designing a fully welded beam to column connection where a 0.5 m section of beam is welded to the web of the column in the shop. The width of the beam is considerably less than the depth of the column. On site, the beam section is to be connected to the remainder of the beam using a splice detail. The connection is specified as a moment connection.

The moment at the connection results in a force of approx 500 kN in the flanges of the beam. Does anyone have any suggestions for designing for this? Would it be advisable to attach a plate to the beam flanges such that the plate is in contact with the column flanges?

 

[ishvaaag]

You may use coverplates over the beam flanges to gain the between-column flanges' width, then also weld there. This way the flanges will receive the brunt of the effort, and not the (relatively) weaker column web.

 

[Lion06]

I agree, the flange plates of the moment connection want to engage the flanges of the column or you could easily have a local web failure in the column. It's also not providing the rotational stiffness that your analysis software is assuming if you only engage the web.

 

[connectegr]

You need column web stiffener plates (horizontal) and an extended web shear plate similar to a field welded moment connection. This can be all shop welded or the web can be shop bolted. The moment should be taken in the column flanges.

http://www.FerrellEngineering.com

 

[connectegr]

Cover plating across the flanges has similar problems to direct welding to the web. Yield line analysis of the plate and weak axis bending of the cover plate. And to you weld the cover plate to the flanges. You cannot put a one sided fillet weld in prying. The cover plate would have to be very thick.

http://www.FerrellEngineering.com

 

[connectegr]

Is there a backup moment beam on the far side of the column?

http://www.FerrellEngineering.com

 

[peru4444]

Thank you for your helpful replies so far. The arrangement I am now considering consists of tapered cover plates welded to the column web and both column flanges. The cover plates are also welded to the beam flanges. The cover plate is 25 mm thick which is thicker than the beam flange (17.3 mm). There is a similar connection on the other side of the column web. I have attached a sketch of a similar connection.

Is this arrangement adequate? How would I check the stresses in the column web? Also, what should I take as the effective length of the weld? Should I just take it as being equal to the column web depth?

 

[connectegr]

This is the detail I described. But, we are calling the stiffener plates by different names. Weld the plates to the column flanges for the beam flange force. If this is excessive the beam flange force can be distributed to the web and flange welds. The flange welds are in shear and the web welds are in tension. The weld lengths are based on the plate dimensions minus corner clips to clear the column fillet.

http://www.FerrellEngineering.com

 

[connectegr]

I noticed something more in your detail. You also have moment connections to the column flanges. The stiffener plates and welds must develope the interaction of these forces.

http://www.FerrellEngineering.com