Moment Connection 2

[jm1]

Hello,

I have what is essentially a 7' x 7' "I" shape made up of W-shape beams supported by a single HSS column 23' tall at the centroid of the "I" shape. This structure is subjected to lateral/longitudinal/vertical loads. In order for the "flanges" of the "I" shape to remain stable there needs to be a moment connection to the "web". I have reviewed quite a few beam/column moment connections but I have not seen a beam/beam moment connection (apart from the splice connection). Can I cope the flanges of the "web" beams and weld to the flanges of the "flange beams", along with a shear tab? Thanks in advance....

jm1

 

[J1D]

jm1,
What's the structure look like? Single 23' tall column supports a 7'x7' "I" section make up wide flange beams? How does this work?
j1d

 

[jm1]

Three 7' long W-shapes oriented as an "I" (X-Z plane if Y is up) mounted 23' supported at the center of the "I" by a single HSS. Like a cantilever with an "I" mounted on its end. Long time since school, and even at that moment connections were like doing the entire 20th century on the last day of a world history class...
jm1

 

[CTW]

Is this correct? Except that the "I" is laying face down and supported at the center of the web by an HSS? Now I'm curious, what is this supporting or being used for?

------------- W-shape
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| W -shape
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------------- W-shape

 

[jm1]

Exactly - it is being used as a support tower for substation bus. The insulators attach at three points along each "flange" of the "I".
jm1

 

[J1D]

Is this bus a shelter/canopy? You can find beam-to-beam moment connection detail from some steel handbooks. Basically, when using weld connection, you need to fillet weld the coped web of the "web" beam to the "flange" beam and groove weld the coped flanges of the "web" beam to the flanges of the "flange" beam, and use stiffener plate if necessary. But no matter what, your "flange" beams will not be very rigid since the torsional stiffness of the "web" beam is very small.
Regards,

 

[jm1]

J1D et al.,
Thanks for the help - it is a support for rigid bus conductors in an electric substation. the "p"s below are where the insulators mount...not much dead load, just problems with wind/seismic horizontal loads. regards - jm1

--p-p-p-- W-shape
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|W-shape
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| | \HSS
| --p-p-p-- W-shape
[\]

_______
I_______I W-Shapes
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||
||
||HSS
||
||
~~

 

[TFL]

you might be alot better of using tubes for the beams.

1. Wide flanges might have an unbraced length problem or torsional problem. tubes are much better.

2. assuming this is outside a tube is a better shape for corrosion there is les surface area or horix surface to collect water