1. What is Bolt Elongation?

Bolt elongation refers to the deformation or stretching of a bolt when subjected to an axial force. It's an important factor in engineering design to ensure proper fastener performance and joint integrity.

2. How Does the Calculator Work?

The calculator uses the bolt elongation equation:

Where:

• \( \delta \) — Bolt elongation (m)
• \( F \) — Applied axial force (N)
• \( L \) — Original length of bolt (m)
• \( A \) — Cross-sectional area of bolt (m²)
• \( E \) — Young's modulus of elasticity (Pa)

Explanation: The equation calculates how much a bolt will stretch under a given load based on its material properties and dimensions.

3. Importance of Bolt Elongation Calculation

Details: Calculating bolt elongation is crucial for proper joint design, preventing bolt failure, ensuring adequate preload, and maintaining joint integrity under operational loads.

4. Using the Calculator

Tips: Enter force in newtons, length in meters, cross-sectional area in square meters, and Young's modulus in pascals. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is typical Young's modulus for steel bolts?
A: For steel bolts, E is typically around 200 GPa (200 × 10⁹ Pa).

Q2: How do I calculate cross-sectional area?
A: For a bolt, A = π × (d/2)² where d is the nominal diameter (for full-diameter calculation) or root diameter (for more precise calculation).

Q3: What is acceptable elongation for bolts?
A: Acceptable elongation depends on application, but typically should not exceed 0.2% of the bolt length for most structural applications.

Q4: Does this account for plastic deformation?
A: No, this equation is only valid in the elastic deformation range (before yielding occurs).

Q5: How does temperature affect elongation?
A: Temperature changes affect both length (thermal expansion) and Young's modulus, which should be considered in high-temperature applications.