Force due to Lateral moment

[waren1991]

Hello Gentlemen,

Can someone guide me on how to calculate the force to be connected from the given Lateral moment of a W beam connecting to a W column(The EOR says to connect a W beam to a W column with fully restrained moment connection for the full lateral moment capacity of the beam). For the gravity moment connection I divide the given gravity moment by beam depth to get the force to be connected.Should I divided the Lateral moment by width of the beam to get the force by Lateral moment?. Thanks for your time!

 

[BAretired]

Well, actually there are two equal and opposite forces required for either a gravity moment connection or a "lateral moment connection". If a welded connection is acceptable, use a full strength butt weld. That should develop the beam section for shear and moment about major and minor axes. If a bolted connection is preferred, use an end plate with minimum of four bolts spaced to suit.

I don't know why the EOR cares about lateral moment from the beam as that results in torsion in the column.

 

[waren1991]

Hello BA...thanks for the response,the above suggestion will resolve my issue...could you tell me how to convert the lateral moment into force as well to decide the number of bolts & weld length?...there are locations where the EOR shows lateral moment value & ask to connect the beam to column for that lateral moment.Thanks in advance

 

[JStructsteel]

The EOR wants a moment connection for lateral load on the beam? Is there nothing bracing it?

 

[waren1991]

Please refer to the attached file for the exact wording of EOR

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1681736815/tips/Lateral_moment_s7hywk.pdf[/url]

 

[L_Bey]

In general delegated design connections need to be stamped by an engineer licensed in the project jurisdiction if the connections have not been designed by the EOR. Are you doing the design of the connections?

Based on the snip you provided it appears that the EOR is noting that the beam is part of the lateral force resisting system of the building, and that the connection needs to be designed for the full moment capacity of the beam. If you want a bolted flange plate connection your connection designer can likely provide you with the appropriate plate size and number of bolts. The other common way to provide a moment connection is a flange weld to the column, with stiffener plates as required.

 

[BAretired]

I misinterpreted your original post. Your latest post clears it up to some extent. I'm not entirely clear on the meaning of the second note on the sketch, but it does not apply to the connection shown.

The column appears to be 'boxed' by plates welded to the ends of the flanges. This will increase the Iy and My of the column.

Beams 1 and 2 are each required to have a fully restrained moment connection to the column. That means the connection must be rigid, in other words, the connection must be designed to resist the lesser of the factored column moment or beam moment.

The connection for Beam 1 must be designed to resist the lesser of Mx of the beam and My of the column; for Beam 2, the lesser of Mx of both beam and column.

 

[waren1991]

Thanks L Bey & BA...I guess I have understood the theory now.