Formula for the tensile stress on a spinning ring

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SUMMARY

The tensile stress on a spinning ring can be calculated using specific formulas derived from Roark's Formulas for Stress and Strain. The equations for radial and tangential stresses are given by: \sigma_r = \frac{3+\nu}{8} \rho \omega^2 \left(a^2+b^2-\frac{a^2b^2}{r^2}-r^2\right) and \sigma_{\theta} = \frac{3+\nu}{8} \rho \omega^2 \left(a^2+b^2+\frac{a^2b^2}{r^2}-\frac{1+3\nu}{3+\nu}r^2\right). Key variables include the outer radius (a), inner radius (b), mass density (ρ), Poisson's ratio (ν), and angular velocity (ω). The maximum radial stress occurs at r=\sqrt{ab}.

PREREQUISITES
  • Understanding of tensile stress and strain concepts
  • Familiarity with Roark's Formulas for Stress and Strain
  • Knowledge of material properties including Poisson's ratio
  • Basic principles of rotational dynamics
NEXT STEPS
  • Study the derivation of stress formulas in Roark's Formulas for Stress and Strain
  • Learn about the implications of Poisson's ratio on material behavior
  • Explore the effects of angular velocity on tensile stress in rotating bodies
  • Investigate material selection for high-speed rotating rings
USEFUL FOR

Mechanical engineers, materials scientists, and anyone involved in the design and analysis of rotating machinery, particularly those focusing on flywheel applications.

boab
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I'm having a problem finding and equation that will give me the tensile stress acting on a spinning ring, like the rim of a flywheel, that is trying to "pull itself apart". The ring has no spokes or disc, but is just a ring spinning on its axis. I need to know how fast the ring can spin before it separates from the tensile stress acting on the material it is made of.
I seem to have stepped in over my head.
 
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Go to the library and look in Roark's Formulas for Stress and Strain.
 
For a ring:

\sigma_r = \frac{3+\nu}{8} \rho \omega^2 \left(a^2+b^2-\frac{a^2b^2}{r^2}-r^2\right)

\sigma_{\theta} = \frac{3+\nu}{8} \rho \omega^2 \left(a^2+b^2+\frac{a^2b^2}{r^2}-\frac{1+3\nu}{3+\nu}r^2\right)

where:
a = outer radius
b = inner radius
\rho = mass density
\nu = Poisson's ratio
\omega = angular velocity

The maximum value of \sigma_r happens at r=\sqrt{ab}
 
Well I thank you very much for the quick reply, and the effort! You have saved the day, and advanced the project.
Cliff

I used to be Cliff, now its "boab: as something got lost in my previous registration.
 

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