Connection deisgn for for weak axis moment/shea

[DeathRay009]

Hi,

I am a newbie in connection design so kindly bear with me. I want to deisgn a steel connection between a beam and column, I am going through the examples in AISC but nowhere have I seen them design a connection for weak axis moment/shear, or when moment/shear exist in strong and weak both axis. I have also gone through other questions in this forum but couldn't find a satisfactory answer. Kindly point me to the right direction in this regard.

And feel free to point out if I have missed any information.

 

[dik]

If connection is to the web or flange, I'd likely use an endplate on the beam, assuming it can fit in the 'web space' and design the end plate and fasteners for the required moment.

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

-Dik

 

[DeathRay009]

Connection is to flange of column, Can u guide me to an example please?

 

[human909]

More picture less words DeathRay009. You really aren't describing your issue well.

If it is weak access beam moment into a column the connection physical design is mostly similar. The analysis of the connection has the compression and tension loads rotated 90degrees and you go from there. Not too hard except now you are putting torsion onto the column which needs to be resolved. Of course this answer only applies if I've correctly guessed your question.

 

[DeathRay009]

https://files.engineering.com/getfi...le=IMG_20242608_0943015102080780615283168.jpg

Kindly find here a simple drawing, No torsion forces will act, joint only needs to be deigned for weak and strong axis moment/shear. Moreover as I stated earlier, I am a newbie and therefore an example would help me a lot in this regard.

 

[human909]

Thanks for the drawing. My guess at the question was correct and my reply stands. The general approach to checking this is not to different to a regular moment connection except the neutral axis is rotated 90 degrees about the x direction. If you have Mx and My then I'd be summing the loads. However as I already mention your COLUMN would then have to resist torsion unless there are similar beams frame into it.

Moreover as I stated earlier, I am a newbie and therefore an example would help me a lot in this regard.

In which case you probably should be asking a suitably experienced college. You should also question whether the minor axis bending can be removed by an alternative load path.

 

[DeathRay009]

The weak axis moment/shear comes from a dead load bolted to the beam in case of earthquake. There is no easy way to give an alternative load path.


Got it.


If you can guide me to a book (guide or example) i'll forever be thankful to you.

 

[WARose]

I am going through the examples in AISC but nowhere have I seen them design a connection for weak axis moment/shear, or when moment/shear exist in strong and weak both axis.

I've typically used the moment connection to transfer both strong & weak axis moments to the columns. It's just a matter of proportioning the utilization(s) for each case. (I.e. you used up X % of the capacity for the strong axis and Y% for the weak axis. Just make sure X+Y<100%.) The procedures for design are very similar for both.

For the case where I have had weak axis forces (but no moment connection at the ends), I've typically treated the simple shear connection like a seated beam connection.

 

[dik]

Just as you've shown and as I've described. It's just a matter of calculating the bolt loads and designing the end plate thickness.

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

-Dik

 

[DeathRay009]

For the case where I have had weak axis forces (but no moment connection at the ends), I've typically treated the simple shear connection like a seated beam connection.

Thanks, I'll look into it.

 

[cliff234]

Have you downloaded the AISC Design Examples publication? (Free to AISC members.) That publication will have connection design examples applicable to what you are looking for. Also, your thread is titled, "Connection design for for weak axis moment/shear" but your sketch shows a beam connection to the strong axis of the column. For shear connections it does not matter. For moment connections it does matter.

 

[DeathRay009]

The connection is not exclusively for weak axis, the title may be a bit misleading. I wanted to know what to do when shear/moment acts in weak axis in addition to the strong axis. I have seen the AISC Design Examples Publication. The moment connections as much as I remember were all evaluated in strong axis with loading occuring in strong axis direction only.

 

[cliff234]

DeathRay009,

For weak axis beam to column flange plate moment connections, the top and bottom flange plates are similar to those used for column strong axis moment connections, with the exception that the sides of the flange plates must be widened in order to weld the plates to the inside faces of the column flanges.

Whereas there are several types of strong axis beam to column moment connections (flange plate, end plate, direct beam to column moment connection), there is really only one practical weak axis beam to column moment connection (the flange plate connection as described in the above paragraph).

The many different types of shear connections are definitely covered in the AISC Design Examples publication.

 

[WARose]

Thanks, I'll look into it.

Anytime. Btw, something I forgot to mention: check the web carefully for this load transfer (to the shear angles acting as a seat in this direction). Sometimes the web can severely limit the amount of load that can be transferred.

 

[DeathRay009]

[Have you downloaded the AISC Design Examples publication?/quote]
Yes I have downloaded that.

[I forgot to mention: check the web carefully for this load transfer (to the shear angles acting as a seat in this direction)./quote]
The beam is being attached to the flange of column.