W Beam to HSS Column Moment Connection

[McMichael05]

I have a moment connection of a W beam to an HSS column. CJP weld of the flanges to the face of the column and a shear tab welded to the column and welded to the web of the beam. Capacity is not the issue but rather HSS Limitations as i have a W16x31 in one case and a W18x35 framing into a HSS5.5x5.5x3/8. What is the reasoning for the Width Ratio limitation and why are these limitations not present in the 15th edition of the AISC Manual. I can only find these limitations in the AISC 360-10.

 

[DrZoidberWoop]

You can make use of eq. 9-30 on pg 9-16, in AISC 15th ed., for your flange forces to the hss wall and then use eq. 10-7 on page 10-153 to design the shear connection.

Side note: Unless it's for seismic detailing concerns or some other spec. reason, a CJP seems like total overkill. Your HSS moment capacity (ASD) from Table 3-13 is only 32.7 ft-kips. Both wide flanges you mentioned are 135 ft-kips (W16) and 166 ft-kips (W18).

 

[dik]

Which AISC documents are you referring to?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[McMichael05]

For the HSS Limitations im referring to Table K1.2A in AISC 360-10. Wondering why the K1.2 Tables are not in AISC 360-16.

 

[dik]

Thanks... I don't know why. Maybe they found an error in the application.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dauwerda]

The Steel Tube Institute did a webinar on the changes (why they were made and what they were).
It can be found here:

https://steeltubeinstitute.org/prod...-16-hss-connection-design-limit-state-tables/

or, here is a link to just the video:

https://vimeo.com/372718469

A major factor was that the old chapter K was very prescriptive and repeated information found elsewhere in the spec, these attributes were considered to be less than ideal and not in conformance with the rest of the the spec so the newest edition made these changes to bring the spec back into alignment with itself.

The limits of applicability were part of prescriptive nature - this was not the original intent. Like other parts of the spec, engineering judgement needs to be used to determine if the presented equations/requirements are applicable to the specific situation being addressed (and therefore they were removed).

The Steel Tube Institute also put together tables to help navigate where to find the information in the 15th edition, found here:

https://steeltubeinstitute.org/resources/aisc-360-16/

 

[dik]

I'm a member of the STI and have been for awhile. I have taken several of their webinars; they are quite good. With membership you can 'purchase' for free half a dozen of their webinars. They are excellent and reasonably technical. Membership is reasonable and well worth the cost when you include the webinars. They have also answered numerous technical questions I have posed... fast and technical. Their 'monthly?' publication also has useful HSS design information in it.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[271828]

The strength is often controlled by the 2016 Specification Equation K5-4. B[sub]e[/sub] from Eq. K1-1 is often very small. When the moment isn't tiny, I almost always end up with some sort of through-plate connection.