Contact stress for pin in hole.
Contact stress for pin in hole.
(OP)
Hello,
I'm looking at a problem on an assembly in tension. This could be assumed to be a clevis pin arrangement where several plates are joined together using a pin. The holes in the plates are clearance holes and are a slightly larger diameter hole. I'd like to calculate the contact stress around the hole cirumference assuming that the plate is made of an elastic isotropic material and the pin is rigid. Can someone point me in the right direction?
Thanks
I'm looking at a problem on an assembly in tension. This could be assumed to be a clevis pin arrangement where several plates are joined together using a pin. The holes in the plates are clearance holes and are a slightly larger diameter hole. I'd like to calculate the contact stress around the hole cirumference assuming that the plate is made of an elastic isotropic material and the pin is rigid. Can someone point me in the right direction?
Thanks





RE: Contact stress for pin in hole.
Look in your machine design text under ball bearings. There should be literature on how curved surfaces interact with each other.
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JHG
RE: Contact stress for pin in hole.
That may overstate the stress around the hole the first time max force is applied, but then again assumptions about fits, surface finish and edge loading may be pretty optimistic.
RE: Contact stress for pin in hole.
Cylinder in a cylindrical groove (a cylindrical groove is a cylinder with a negative radius)
The maximum contact pressure between two curved surfaces depends on:
– Type of curvature (sphere vs. cylinder)
– Radius of curvature
– Magnitude of contact force
– Elastic modulus and Poisson’s ratio of contact surfaces
Design of Machine Elements, Spotts, 6th ed PP443
Po = Maximum compressive stress
P1 = Force
Po=0.591*((P1*E1*E2)(1/R1-1/R2)/(E1+E2))**.5
RE: Contact stress for pin in hole.
Look in most good Strength of Materials, Theory of Elasticity, or Machine Design text books, and look for Hertz bearing stresses. The tighter the fit btwn. the pin and the hole the lower the peak bearing stress. Some yielding in bearing is almost unavoidable to cause a satisfactory bearing condition, and this is usually o.k. Also, look at the design of structural eye bars, as in bridges and the like; and lifting lug plates and clevis pin holes, as in ASTM BTH-1. There is more to the problem than just the bearing stress btwn. the pin and the hole in the plate. The pin does bend a little even if you protest to the contrary, and the clear space btwn. the plates and/or clevis (the faying surface clear space) causes some of this. If the plates are not wide enough and thick enough you can get substantial tension and bending stresses at about 3 & 9 o’clock on the pin hole, at the I.D. of the hole, a combined stress condition.
RE: Contact stress for pin in hole.
RE: Contact stress for pin in hole.
You get that message because the FEA is seeing a contact area of zero, resulting in a divide by zero error. I don't know enough about any FEA software to have any confidence in results showing computing errors.
Roark's Equations for Stress and Strain has a section on Bodies in Contact Undergoing Direct Bearing and Shear Stress. This might help.
--
JHG
RE: Contact stress for pin in hole.
RE: Contact stress for pin in hole.
RE: Contact stress for pin in hole.
RE: Contact stress for pin in hole.