📐 Hoop Stress Formulas
σ_h = Pr/t (Thin-walled)
σ_h = P(r² + R²)/(R² - r²) (Thick-walled)
σ_h = PD/(2t) (Thin-walled, diameter)
σ_axial = Pr/(2t) (Axial stress)
σ_h = hoop stress, P = pressure, r = radius, t = thickness, R = outer radius, D = diameter
💡 Tips
- Thin-walled assumption: t/r < 0.1 (10% rule)
- Hoop stress is maximum at the inner surface
- Axial stress is half of hoop stress for closed ends
- Consider temperature effects on material properties
- Account for corrosion allowance in thickness calculations
- Use appropriate safety factors for pressure vessels