1. What is Hoop Stress?

Hoop stress is the stress exerted circumferentially in both directions on a cylinder when pressure is applied. It is a critical factor in designing pressure vessels like water tanks, pipes, and boilers.

2. How Does the Calculator Work?

The calculator uses the hoop stress formula:

Where:

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

Explanation: The formula calculates the circumferential stress in a thin-walled cylindrical pressure vessel. It assumes uniform internal pressure and a wall thickness much smaller than the radius.

3. Importance of Hoop Stress Calculation

Details: Accurate hoop stress calculation is crucial for designing safe pressure vessels. It helps determine the appropriate wall thickness to prevent failure under internal pressure, ensuring structural integrity and safety.

4. Using the Calculator

Tips: Enter pressure in pascals (Pa), radius in meters (m), and thickness in meters (m). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What units should I use for the inputs?
A: The calculator uses SI units: pressure in pascals (Pa), radius in meters (m), and thickness in meters (m). Make sure all inputs are in these units for accurate results.

Q2: Is this formula valid for all types of pressure vessels?
A: This formula is specifically for thin-walled cylindrical pressure vessels where the wall thickness is less than 1/10 of the radius. For thick-walled vessels, more complex formulas are needed.

Q3: What is a typical safety factor for water tanks?
A: Safety factors typically range from 2 to 4 depending on the application, material properties, and regulatory requirements. Always consult relevant engineering standards.

Q4: Can I use this calculator for pipes?
A: Yes, this formula applies to any thin-walled cylindrical pressure vessel, including pipes, as long as the thickness is much smaller than the radius.

Q5: How does temperature affect hoop stress?
A: Temperature changes can affect material properties and induce thermal stresses. For high-temperature applications, additional calculations considering thermal expansion may be necessary.