Shear Tab/Tube connection? 1

[connectegr]

The check for punching shear is correct K1-10. Also check the HSS wall for the weld. Design Guide 24 has a table for minimum wall thickness related to weld size. And as you mentioned the shear plate is designed per 10-101 in the 13th Edition.

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[connectegr]

A little more info. SEE attached, design example for 13th Ed

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[SteelPE]

Thanks for the info.

It looks like the HSS shear rupture is going to control the design of the connection (tmin>6.19D/Fu). Therefore, as a general rule of thumb, it appears that you should use 5/16 thick tube as a minumum tube thickness for a tab plate connection (because a 1/4" tab plate requires 3/16 welds).

In this instance a 1/4" tab would require a tmin=0.32017.

 

[ToadJones]

is tmin the thickness of the tab or the tube wall?

 

[ToadJones]

never mind...

 

[connectegr]

Remember the wall thickness for design is 93% of t, due to mill tolerances. If 0.32 is required, then the nominal thickness should be 3/8".

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[ToadJones]

question is for me, is "D" the required weld size based on strength, or the size actually used based on thickness of material?

 

[connectegr]

In 13th Edition the weld size for a single plate is required to develop the plate, but not exceed 5/8(t). The tables in 13th Ed chapter 10 provide weld sizes equal to 5/8(t). To achieve the tabulated capacities, the HSS wall must be adequate for the tabulated weld size.

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[connectegr]

We use the attached reference on our HSS single plate standard. In most cases we use 3/8" Plates with 1/4 fillets.

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[ToadJones]

in this case the weld size "D" for a two-sided fillet is 2 x nominal weld size correct?
for example, a quarter inch shear tab weld with a two sided 3/16" fillet would have D=6, correct?

I also dont see where it says that the weld size cannot exceed (5/8)t

 

[SteelPE]

5/8" tp is on page 10-101 under design checks.

 

[connectegr]

No designing the weld using table Table 8-4, already considers that there are to welds. Therefore, 3/16 fillets is D = 3

http://www.FerrellEngineering.com

 

[connectegr]

SteelPE
Another small thought, we rarely calculated shear tabs by determining the minimum plate thickness. Most fabricators prefer to use a standard plate thickness, such as 3/8 bar. Therefore we work the other direction and verify that the wall thickness is sufficient. Most of our projects have columns walls 3/8" or greater, or narrow columns with 5/16 walls. If the minimum wall thickness can not be satisfied per the table above, we provide a "special" case detail.

For a 3/8 plate, K1-10 is satisfied with a 5/16 wall. The b/t ratio is independent of the plate thickness, and 5/16 wall is adequate for 10" columns and less.

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