Quick guide
How to use this calculator
- Choose the analysis mode that matches the physical model before entering values.
- Enter properties, geometry, loads, states and coefficients from one consistent unit and sign convention.
- Use the intermediate outputs to audit the relationship, then retain the stated idealization before applying it.
Calculation method
Transparent engineering model
Cylinder: σh=pD/(2t), σL=pD/(4t). Sphere: σ=pD/(4t). Thin-wall ratio D/t is reported rather than silently approved.
The calculator evaluates only the declared relationship and preserves visitor-entered assumptions rather than selecting materials, factors, components or standards.
Worked example
Worked example
A cylindrical shell with p=2 MPa, D=1 m and t=10 mm has ideal hoop stress 100 MPa and longitudinal stress 50 MPa when one consistent unit basis is used.
Cylinder: σh=pD/(2t), σL=pD/(4t). Sphere: σ=pD/(4t). Thin-wall ratio D/t is reported rather than silently approved.
Supported inputs
Precision and limits
Analysis, not approval
Ideal membrane equations exclude heads, openings, nozzles, weld efficiency, corrosion allowance, external pressure, local loads, fatigue, temperature gradients and every code-specific requirement.
Standards and properties
Material properties, allowable values, load combinations, safety factors, correlations, manufacturer data, codes and jurisdictional requirements are not supplied automatically.
Units and precision
Use one consistent unit basis. Results retain working precision but cannot be more accurate than the entered measurements and properties.
Privacy
Entered engineering values and results stay in this browser and are not sent to analytics or third parties.