huangyhg

pin design
hi all,
i have designed a pin (which has got circular cross section),thats going to be in shear,i have assumed the pin to be short coloumn and considered only shear.
i did try to do some basic bending stress calculation ,but the bending stress is way above the allowable,while shear stress is below the allowable.
i am bit confused about this reponse.i thought short coloumns fail more due to shear than baending.
i appreciate your comments on this.
thanks
badri07.
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dont you mean a beam? a column usually decribes an axially loaded
thank you for your post parrot77,
yes,what you are saying is right,infact its a beam connected between adjacent plates,this has got double shear.on bending calculation i just did a basic hand calc to check the bending stress --->sigma(b)=m/z.this calculation was performed assuming it to be a simply supported beam with point load in the center.
infact i did an fea on the pin using beam elemnts,this is giving an bending stress of sigma(b)=133mpa.
thanks
badri07
for significant bending to be induced there will need to be a substantial gap between the outer plates and the middle plate where the load is applied. the pin is then forced to span between the two outer plates. if however the plates are side by side and the pin is threaded through as per most common connections then only shear will be critical.. much like a regular beam loaded adjacent a support.
hi badri07
just post your pin size, distance between supports and load applied and we can maybe help further.
regards
desertfox
maybe this will help:
desertfox,
the thickness of the connecting plates will also be required as bearing stresses may be critical.
hi all,
thank you all for your time,the distance between the two plates is around 150mm and the 2.22x10exp6 is applied on to the pin,the dia of the pin is 126.5mm(5").
thanks
badri07.
that's some pin ... shear and bending margins are dependent on different aspects of the geometry, so it's not surprising that it's critical in bending (particularly if its a solid pin).
e looks funny, units ?
what end conditions did you assume (in calculating the moment in the pin) ? ... i'd suspect that fixed would be appropriate.
where did you apply the shear forces ? mid-thickness would be conservative, closer to the mating plane is more realistic.
did you allow plastic bending ?
how is this load applied to the pin? by a third middle plate? if so what are the thickness of all 3? the thickness would be governed by bearing stresses. what is the load? i didn't underdstand your annotation
hi rb1957,
e=2.0e+005mpa,and the load applied in the pin 2.5sh tons,thats 2.22e+006n(as in my previous post),boundary condition for mmax is simply supported,i applied the shear force in the center of the beam,and the moment i calculated applies to elastic bending.
thanks
badri07

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