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Design of a Triplate

Design of a Triplate

Design of a Triplate

(OP)
We had to double check the calculation made by a chinese engineering team and we figured out almost everything except the formula at row 34. Can anybody help? https://i.imgur.com/aJpB75K.jpg

RE: Design of a Triplate

The expression on line 34 is equivalent to:
(T/dB)(R2+r2)/(R2-r2) = kT/dB
where r is the radius of the pin.

With R = 350mm and r = 92.5mm, k = 1.15

So σ3 = 1.15T/dB

Not sure that is much help. Doesn't make a lot of sense to me.


BA

RE: Design of a Triplate

Is expression on Line 34 =

(R^2+r^2)/(R^2-r^2) = k ?

Dik

RE: Design of a Triplate

Correct, Dik.

BA

RE: Design of a Triplate

(OP)
Being k a stress concentration factor? But where that formula comes from?

RE: Design of a Triplate

(OP)
Found it! Roark table 13.5. Thanks mate

RE: Design of a Triplate

BART:

Didn't have my calculator handy... It looked like the k value wasn't in keeping with the R values...

Dik

RE: Design of a Triplate

Dik,
R = 350; d = 185, so r = 92.5
k = (3502 + 92.52)/(3502 - 92.52) = 1.15 (looks okay)

An equivalent expression is: k = (Aoc+Ap)/(Aoc-Ap)

where Aoc is the area of the outer circle and Ap is the area of the pin.

BA

RE: Design of a Triplate

Thanks... I did run the numbers through after I posted and was going to add another comment... again, thanks.

Dik

RE: Design of a Triplate

Roark Table 13.5 appears to be for a thick walled cylinder with either internal or external pressure acting. The diagram prepared by the Chinese engineering team does not appear to be talking about pressure. Instead, they are referring to a tension T which is applied "at the point of tension", wherever that may be.

I am not sure that Table 13.5 is appropriate to the actual loading conditions, but I do not have a clear picture of a "triplate" or how exactly it is used. The diagram is not clear.

BA

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