1. What is Hoop Stress?

Hoop stress is the stress exerted circumferentially in both directions on every particle in the cylinder wall when it is subjected to internal pressure. It is a crucial parameter in pressure vessel design and piping systems.

2. How Does the Calculator Work?

The calculator uses the hoop stress equation:

Where:

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

Explanation: The equation calculates the circumferential stress in a thin-walled cylindrical pressure vessel subjected to internal pressure.

3. Importance of Hoop Stress Calculation

Details: Accurate hoop stress calculation is essential for designing safe pressure vessels, pipelines, and other cylindrical structures to prevent failure under internal pressure.

4. Using the Calculator

Tips: Enter internal 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: Is this formula valid for thick-walled cylinders?
A: No, this formula is specifically for thin-walled cylinders 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 temperature affect hoop stress?
A: Temperature changes can cause thermal expansion, which may increase or decrease hoop stress depending on constraints and material properties.

Q5: What materials are commonly used for pressure vessels?
A: Common materials include carbon steel, stainless steel, aluminum, and various alloys chosen for their strength, corrosion resistance, and temperature tolerance.