aisc check for single plate 3

[wrxsti]

hello once again eng-tips community

i noticed in the k-6 example for aisc

for HSS rupture at welds check

Equation 9-2 from manual

HOWEVER 9-2 is for one side of weld
equation 9-3 is for two sides welded

should 9-3 be used for this scenario instead of 9-2?

 

[SethGuthrie]

The plate has welds on both sides, but the HSS column was welds only on the outside.

 

[MGaMart]

Equation 9-2 still holds valid for the HSS. There are two shear rupture planes which would exist on the HSS, one for each vertical weld. Equation 9-3 would only be valid if vertical welds existed on both sides of the HSS wall (the outside and inside) along the same vertically cut section (which is typically not physically possible given our limited access for welding on the inside of an HSS tube). Because the welds on the HSS are separated a distance equal to the thickness of the shear tab, two shear rupture planes are created, making equation 9-2 the appropriate check. Equation 9-3 would be valid for a check on the shear tab plate, as the welds exist in the same plane of a vertically cut section on the shear tab.

 

[wrxsti]

thanks guys


in aisc 13
its stated as
"..For fillet welds with Fexx = 70 ksi on both sides of the connecting element, the minimum thickness required to match the shear rupture strength of the connecting element to the shear rupture strength of the base metal is..."

which confused me a bit.

which is now in the aisc 15 as

"..For fillet welds with Fexx = 70ksi only on ones ide of an element, the minimum base metal thickness required to match the shear rupture strength of the weld is.."

which i posted here and didnt read XD

 

[r13]

Equation 9-3 is for the case that both weld lines are effecting on a common shearing plane (connection plate). Whereas equation 9-2 is for the case that each weld line effecting on a single shearing plane (there are total two shearing planes on the HSS web).

 

[r13]

Sketch.

 

[wrxsti]

thanks r13

 

[r13]

You are welcome. It take some time to be familiar with code wordings