1. What is True Stress?

True stress is the actual stress experienced by a material during deformation, accounting for the changing cross-sectional area. Unlike engineering stress which uses the original area, true stress provides a more accurate representation of material behavior under load.

2. How Does the Calculator Work?

The calculator uses the true stress formula:

Where:

• \( \sigma_{true} \) — True stress (Pa)
• \( \sigma_{eng} \) — Engineering stress (Pa)
• \( \varepsilon_{eng} \) — Engineering strain (dimensionless)

Explanation: The formula accounts for the increased stress due to reduction in cross-sectional area during deformation.

3. Importance of True Stress Calculation

Details: True stress is essential for accurate material characterization, especially in plastic deformation where significant changes in cross-section occur. It's crucial for finite element analysis and material modeling.

4. Using the Calculator

Tips: Enter engineering stress in Pascals (Pa) and engineering strain (dimensionless). Both values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: When should I use true stress vs engineering stress?
A: Use engineering stress for initial elastic deformation and true stress for plastic deformation where cross-sectional area changes significantly.

Q2: How does true strain differ from engineering strain?
A: True strain accounts for the instantaneous length changes, while engineering strain uses the original length as reference.

Q3: Is this formula valid for large deformations?
A: Yes, this formula remains valid for large plastic deformations where necking occurs.

Q4: What about volume conservation during deformation?
A: The formula assumes volume conservation (valid for most metallic materials).

Q5: Can I use this for compressive stresses?
A: Yes, but ensure you use appropriate sign conventions for compressive stresses and strains.