By Zencalcy Editorial TeamLast reviewed About us
A thin spherical pressure vessel contains internal pressure and develops a uniform membrane stress in all directions. The stress is the same in any meridian section.
Membrane stress in a thin-walled spherical vessel under pressure.
σ = p r / (2 t)
σ is the membrane stress, p the internal gauge pressure, r the inner radius and t the wall thickness. This stress is biaxial and equal in all directions.
| Symbol | Meaning |
|---|---|
| σ | Membrane stress. |
| p | Internal gauge pressure. |
| r | Inner radius. |
| t | Wall thickness. |
σ = p r / (2 t) = 3×10⁶ × 0.5 / (2 × 0.005) = 150 MPa.
Continue with the Pipe Wall Thickness Calculator, Stress Calculator, or the Strain Calculator — or browse more materials and elasticity tools and all physics calculators.
Because the stress is shared in two directions in a sphere whereas a cylinder has a directional hoop stress.
Results are computed from the standard equations of classical mechanics. Unit conversions use the SI definitions published by NIST. Air resistance is ignored unless the calculator names a drag model.
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Content updated: September 2026