Predicting elastic and plastic wheel deformation

AI Thread Summary
To predict elastic wheel deformation for a steel wheel with specified dimensions and material properties, one approach involves calculating the deformation in finite layers, applying shear modulus through each layer to determine finite stress. The contact pressure can be estimated using a formula that incorporates the volume of the displaced wheel and the Poisson ratio. However, this simplistic model may overlook critical factors, especially when assessing conditions for plastic deformation at the contact area. The discussion also highlights the relationship between contact stresses and deformation, suggesting that integrating stress in the z-direction could provide insights into overall strain. Understanding these principles is essential for accurately predicting wheel behavior under load.
RayRoc
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I am trying to predict elastic wheel deformation. I am not quite sure how to do it. How might one approach the problem?

Take a steel wheel: 6 in. diameter, 2 in. thick, with a contact force of 1000lbs

E = 30,000,000 psi
Poisson ratio: .27

Would one calculate this in finite layers? Considering sections at a time and applying shear modulus through the layers to find the finite stress of the steel?

I have seen the stress distribution of a steel wheel against a track, and it looked like a strait coulomb from the contact area to the axial. Can it be as simple as:

Contact pressure = (volume of wheel displaced/ volume of .5 the wheel cross section) * Poisson ratio * E

There are of course many effects not realized by such a simplistic view especially when one wants to find the conditions that will cause plastic deformation at the contact area; which is ultimately what I want to know.

The gears in my head have failed, the more I think about this problem the louder the grinding noises.
 
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Contact stresses for a cylinder on a cylinder are as follows. The area of contact is a narrow rectangle of width 2b, and length l, where l is the length of the cylinders, and
b = \sqrt{ \frac{2F}{\pi l} \frac{ (1-\nu^2_1)/E_1 + (1- \nu^2_2)/E_2}{1/d_1 + 1/d_2} }
With the maximum pressure being
p_{max} = \frac{2F}{\pi b l}
You can apply this to a cylinder in contact with a plane by making d_2 = \infty

edit: Just seen that you're looking for deformation, not stress. Let's see...stress in the z-direction, perpendicular to the contact line is:
\sigma_z = \frac{-p_{max}}{ \sqrt{1+ z^2/b^2}}
Perhaps you could integrate that from z = 0, to z = r to calculate the summation of strain?
 
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