looking for weld stregth chart
looking for weld stregth chart
(OP)
looking for a good chart on the web that compares fillet size vs ultimate or yeild strength. 7018 welds on mild steel plate. need 5/16's now but would like a chart for future reference
thanks
thanks





RE: looking for weld stregth chart
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RE: looking for weld stregth chart
"Design of Weldments" by Omer Blodgett
This book has charts on allowable stresses for weldments expressed in psi/inch of weld, and fillet weld size. If you deal with welding on a regular basis, you should have it for useful reference material.
RE: looking for weld stregth chart
RE: looking for weld stregth chart
or .4(Sty)(t) = .4(36000)(1.125)= 16,200lb?. so the plate will yield before the weld shears? The load being applied perpendicular to the weld, what about longitudinal?
Thanks
RE: looking for weld stregth chart
RE: looking for weld stregth chart
for .4(Sty)(t) you use fillet size for (t).
Now for longitudinal loading the formulae stay the same?
I thought maybe perpendicular loading would take into account bending moments. Taking into account how high the load is applied.
such as PxL=(sigma)(W)(a)(D+a)
W=length of weld
D= plate thickness
L= plate height
a= weld throat
P= load
so substituting a a failure stress in psi and solving for P will get me my failure load?
or am i looking into this too hard
this equation was what i was originally using when i was looking to find the yeild strength of a 5/16" weld
RE: looking for weld stregth chart
Therefore, the allowable strength of the 0.3125 inch fillet weld you mentioned is 813 N/mm (4640 lbf/inch) or 0.40(Sty)(t), whichever is less, where Sty = plate tensile yield strength (250 MPa for your plate), and t = plate thickness.
For simplicity, if the load is perpendicular to your weld, you could assume the weld strength is still 4640 lbf/inch. So if your load were parallel to the plate and perpendicular to the weld, that would be, in your case, 4640(2 welds)(8) = 74240 lbf. (And obviously the plate tensile strength wouldn't govern here.) If the load is instead parallel to your weld, the shear strength of the plate through its thickness is 0.40(36000)(1.125)(8) = 129600 lbf (which doesn't govern) and the weldment strength is 4640(2 welds)(8) = 74240 lbf.
But I now see your perpendicular load is perpendicular to the plate and perpendicular to the weld. So I agree with your equation, except change the "D+a" to just "D". Hence the weld stress due to bending would be sigma_y = P*L/(b*D*a), where b = plate length = 8 inch. But you also have weld stress perpendicular to the plate, which would be sigma_z = P/(2*b*a). So I think that would be sigma = (sigma_y^2 + sigma_z^2)^0.5. Therefore, ensure sigma*b is less than the weld allowable strength.
RE: looking for weld stregth chart