1. What is Permanent Elongation?

Permanent elongation refers to the non-recoverable deformation of a material after being subjected to stress and then unloaded. It represents the portion of total elongation that remains after the elastic (recoverable) component is removed.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( \text{Permanent} \) — Permanent elongation (m)
• \( \text{Total} \) — Total elongation under load (m)
• \( \text{Elastic} \) — Recoverable elastic elongation (m)

Explanation: The total elongation consists of both elastic (temporary) and plastic (permanent) components. When the load is removed, only the elastic portion recovers.

3. Importance of Permanent Elongation Calculation

Details: Measuring permanent elongation is crucial for understanding material behavior under stress, assessing ductility, and predicting performance in engineering applications.

4. Using the Calculator

Tips: Enter total elongation and elastic elongation in meters. Both values must be positive numbers, and total elongation should be greater than or equal to elastic elongation.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between elastic and permanent elongation?
A: Elastic elongation is fully recoverable when load is removed, while permanent elongation remains as plastic deformation.

Q2: What materials typically show permanent elongation?
A: Ductile materials like metals, plastics, and rubber exhibit permanent elongation after exceeding their elastic limits.

Q3: How is this measurement used in quality control?
A: It helps verify material properties meet specifications for ductility and deformation characteristics.

Q4: What factors affect permanent elongation?
A: Material composition, temperature, strain rate, and previous deformation history all influence results.

Q5: How does this relate to yield strength?
A: Permanent elongation begins when stress exceeds the material's yield strength, marking the transition from elastic to plastic deformation.