Stresses in hollow pins
Stresses in hollow pins
(OP)
Will someone please tell me the formulae for calculating shear and bending stresses in hollow pins. My old textbooks only discuss solid pins. Can you suggest a good reference book?
Thanks
Albie2
Thanks
Albie2





RE: Stresses in hollow pins
S = F/A = F/(PI * r^2)
for a hollow pin
S = F/A = F(PI * (ro - ri)^2
not much to it...
Wes C.
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RE: Stresses in hollow pins
Wes C.
------------------------------
No trees were killed in the sending of this message, but a large number of electrons were terribly inconvenienced.
RE: Stresses in hollow pins
for shear stresses, the same formulae applies for solid bars and tubes (VQ/It) ...
RE: Stresses in hollow pins
RE: Stresses in hollow pins
S = F/A = F(PI * (ro^2 - ri^2))
essentially you are subtracting the area of the hole
from the area of the solid pin to get the rim
area as the above formula indicates.
RE: Stresses in hollow pins
S = F/A = F/(PI * r^2)
for a hollow pin
S = F/A = F(PI * (ro - ri)^2
I agree to wes the formulas are listed above
RE: Stresses in hollow pins
S = F/A
For a hollow pin:
A = PI*ro^2-PI *ri^2 = PI *(ro^2-ri^2)
(NOT PI * (ro - ri)^2)
and
S=F/(PI*(ro^2-ri^2))
RE: Stresses in hollow pins
Thanks gearguru!
RE: Stresses in hollow pins
I've always understood this as the near-vertical side walls taking the shear (as in the web(s) of an I or box beam), where the top and bottom portions do most of the work in bending.
RE: Stresses in hollow pins
Could you give the resource for that conclusion?
Interesting!
It does seem that there would be some difference
as to whether it was a thin vs heavy cross section
and/or rim thickness vs diameter.
RE: Stresses in hollow pins
AISC Steel Construction Manual, 13th Edition, Spec. Chapter G6, Round HSS.
"The nominal shear strength, Vn, of round HSS, according to the limit states of shear yielding and shear buckling, is
Vn = FcrAg/2 "
Fcr is the critical buckling stress and depends on D/t ratio, Ag is the gross area, and HSS stands for Hollow Structural Section which pertains to a specific type of pipe used in structures.
Note that the AISC spec is not intended to design watchband pins and the like, but I've used it for hollow pins as small as 1/2".
My first post alluded to other failure modes such as local buckling; this equation and the ones further along in the text take those issues into account. However, if you have a good feel for the material and proportions of the pin and know it won't fail in those modes, I think the S=2F/A number is a good one to compare to the yield stress.
RE: Stresses in hollow pins
Thanks!
RE: Stresses in hollow pins
If in 2, then the swearingen's formula is what I would use also. If in one location only, then I'd prefer to use mine formula.