1. What is Hoop Stress?

Hoop stress is the circumferential stress in a cylindrical or spherical pressure vessel when subjected to internal or external pressure. It's a critical parameter in pressure vessel design and structural integrity assessment.

2. How Does the Calculator Work?

The calculator uses the hoop stress equation:

Where:

• \( \sigma \) — Hoop stress (Pa)
• \( P \) — Internal pressure (Pa)
• \( r \) — Radius of the cylinder (m)
• \( t \) — Wall thickness (m)

Explanation: The equation calculates the stress acting circumferentially around the cylinder wall, which is typically the maximum stress in thin-walled pressure vessels.

3. Importance of Hoop Stress Calculation

Details: Accurate hoop stress calculation is crucial for designing safe pressure vessels, pipelines, and storage tanks. It helps determine appropriate wall thickness and material selection to prevent failure under operating conditions.

4. Using the Calculator

Tips: Enter pressure in Pascals (Pa), radius in meters (m), and thickness in meters (m). All values must be positive and non-zero.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between hoop stress and longitudinal stress?
A: Hoop stress acts circumferentially around the cylinder, while longitudinal stress acts along the length of the cylinder. Hoop stress is typically twice the longitudinal stress in thin-walled cylinders.

Q2: When is this equation valid?
A: This equation is valid for thin-walled pressure vessels where the wall thickness is less than about 1/10 of the radius.

Q3: What safety factors should be considered?
A: Engineering design typically includes safety factors of 2-4 depending on the application, material properties, and regulatory requirements.

Q4: How does material strength affect hoop stress calculation?
A: The calculated hoop stress must be compared to the material's yield strength and ultimate tensile strength with appropriate safety margins.

Q5: Can this calculator be used for other materials besides steel?
A: Yes, the hoop stress equation applies to any isotropic material, but material properties and safety factors will vary.