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Hertzian Contact Stresses - Please Help!!

Hertzian Contact Stresses - Please Help!!

Hertzian Contact Stresses - Please Help!!

I'm trying to show my working for maximum shear stress for a sphere on a flat plate. The answer is 202.9 MPa.

Please can somebody show me the working out, I'm stuck at calculating the principal stresses and I cannot understand the z value, which is apparently 0.225mm.

When I input the values below into the equation for principal stress, I get 2.57x1010Pa, which gives me the wrong value when inputted into the shear stress eq.

I'm losing my mind over this!

Radius of sphere = 50mm, E = 200GPa, Poisson's Ratio = 0.3, Force = 300N, Pmax = 654.5MPa, z=0.225mm

RE: Hertzian Contact Stresses - Please Help!!

A diagram of the scenario you're trying to analyze will help tremendously.

RE: Hertzian Contact Stresses - Please Help!!

I have had good understanding on contact stresses from "Formulas for Stress, Strain, and Structural Matrices" by Walter D. Pilkey, John Wiley & Sons, chapter 9.

The Z parameter is distance from contact area to location of maximum shear stress.

The problem is thus

Go to the library or bookstore or internet ...

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