Wind Uplift
Wind Uplift
(OP)
What is the method of calculating an uplift capacity of a single 1/2" or 3/4" puddle weld from a metal deck to a steel members subject to a net uplift force due to wind.
Say calculated wind uplift is 40 psf, DL on the deck is 15 psf, deck is 20 ga B-Deck (1 1/2"), welds are at 12"oc at the supports, typical beam spacing is 8'-0" oc. Net uplift to resist would be 40 - 15 or 25 psf.
Connection will be not be a problem by inspection but for a rigorous check what would we do? Thanks for the advice.
Say calculated wind uplift is 40 psf, DL on the deck is 15 psf, deck is 20 ga B-Deck (1 1/2"), welds are at 12"oc at the supports, typical beam spacing is 8'-0" oc. Net uplift to resist would be 40 - 15 or 25 psf.
Connection will be not be a problem by inspection but for a rigorous check what would we do? Thanks for the advice.






RE: Wind Uplift
Just a small note, make sure you apply the wind load for components and cladding with the proper area. Also, I would not deduct too much dead load. This is conservative. Welders do not always do a nice job with puddle welds.
RE: Wind Uplift
and it offers the following:
Nominal tension load Pn on each arc spot weld between sheet and supporting member shall not exceed:
Pn = 0.7 x t x da x Fu
Where:
da = average diameter of the weld at mid-thickness of t (da = d - t) with d = visible diameter of the weld and t = total thickness of your gage plate.
Fu = ultimate stress of your gage plate
They specify that the following limitations apply:
e(min) >= d
where e = Force / (Fu x t)
The electrode is >= 60ksi
That Fu <= 60 ksi
That t >= 0.028 inches.
Keep in mind this is a bit dated (1989)
RE: Wind Uplift
http://www.njb-united.com/usd/ddds/data18r.pdf
RE: Wind Uplift
Using JAE's equation, I get the following:
Pu = 0.7 x 0.0359 x (0.75-0.0359) x 45 ksi = 0.807 k
Using Lutfi's chart, I get 1710 # (Figure 1, 0.75" puddle weld, A653G33, 20 ga.)
Any idea why the difference? Table is Tensile "Strength" and indicates Omega of 2.5. Thus allowable should be 1710#/2.5 = 684#. This is much closer to results from AISI.
Am I interpreting this correctly?
Regards.
RE: Wind Uplift