Tensile Test of Slip Ring - Working out Tensile Strength

[Delvaurius]

All,

Through work, I've recently been tasked with investigating a very old tensile test technique, according to BS HC 403:1977 (now withdrawn).

Essentially, you take a ring. Anywhere along it you make a slit all the way through. You then pull that ring in a tensile machine, ensuring that the slit is perpendicular to the direction of force.

The standard then states, to work out the tensile strength, use the equation:

S = (3*P*((D/t)-1)) / b*t

S = Stress, P = Load, D = Outer Diameter, t = radial thickness, b = width.

Now I get the whole thing over (b*t) where b*t is the cross sectional area of the ring, meeting S=F/A.

How is Force = 3P((D/t) - 1) derived?

Thanks for any help!

 

[JBA]

In your converted formula F = P; instead, you should be seeking the derivation of the original formula as stated.