homework help ( 3RD year welding)

[becks101]

Need help, just finsihed testing tensile strengths and need to calculate the " breaking load" I can't find a formula for this? Any help greatly apprecited

[killramos]

In not in welding or anything but I'm taking a strengths class for mech engg right now so maybe it would apply. In general if your tensile strengths are in N/m^2 or similar units then multiplying that by the cross sectional area will give you the load required to break the joint. I'm not sure what kind of loading you are looking at though because with different types of loadings come different ways to analyze the failure.

Just finished writing up a pre lab for the course so I thought I'd put in what I can, sorry if it doesnt help much.

[GTI CANADIAN]

Let's say your tensile strength is 50,000psi. That means it takes 50,000 pounds to break 1 square in. Let's say u have a weld with a 1/4" leg and 8inch length. Assuming the material fails in the leg of the weld. The force required to break that weld would equal the area of failure (Leg x Length) X the tensile strength. So ((.25x8) x 50000). Which in this case equals a 100,000 pounds breaking force required.

[Penis McNickels]

To sum up GTI's post

P = Fu*A


P = Load
Fu = ultimate tensile stress/strength
A = Area

Limit states resistance factor (phi) may or may not be applicable.