Shear Pin Design
Shear Pin Design
(OP)
I am trying to design a shear pin that will connect two drive shafts. I can calculate the shear stress that will be applied to the pin, however in order to design the pin to fail at a given stress level I have to employ a certain failure criterion. Any suggestions on how to relate the yield/tensile strength of a given material to the shear stress at which the pin will actually separate?





RE: Shear Pin Design
E = 2*G*(1+v)
E = Elastic modulus
G = Shear modulus
v = Poisson's ratio
so for common steels assuming E = 30,000,000 psi and v = .33 Then G = 11,278,196 psi
You should also use Mohr's Circle.
There are several failure theories that can be used such as the Von Mises and the Maximum Shear theory.
Remember in shear pins the failure (breakage) occurs at the ultimate strength not at the yield strength.
Regards
Dave
RE: Shear Pin Design
RE: Shear Pin Design
τ = 0.6 · σ
where
τ is the shear stress
and
σ is the tensile stress
Testing is used when certainty is required.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Shear Pin Design
Don't introduce sharp notches for failure because your pins will fatigue.
If you are making this product to sell to someone make sure to uniquely mark the pins so that you can tell if someone has duplicated your original pins.
Buy your material to a specification and test it.
RE: Shear Pin Design
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Shear Pin Design
RE: Shear Pin Design
Von Mises is a YIELD criterion, not a fracture one. Fracture is much more random, so three decimal precision is unwarranted in predicting shear fracture strength from tensile fracture strength.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.