EngiRef / Materials Engineering Formula
True Stress
True Stress: Stress based on instantaneous area. A Stress & Strain formula in materials engineering. Variables σₜ, σₑ and εₑ, each with SI and imperial units.
Stress & Strain
Specification
- Name
- True Stress
- Discipline
- materials
- Category
- Stress & Strain
- LaTeX
- \sigma_t = \sigma_e(1 + \varepsilon_e)
- Description
- Stress based on instantaneous area
- Conditions
- Uniform deformation before necking; constant volume assumption
- Can solve for
- σₜ, σₑ, εₑ
- Tags
- true, stress, instantaneous, area
Variables
| Symbol | Name | Unit | Si Unit | Imperial Unit |
|---|---|---|---|---|
| σₜ | True Stress | Pa | Pa | psi |
| σₑ | Engineering Stress | Pa | Pa | psi |
| εₑ | Engineering Strain | - | - | - |
Common questions
- What is the True Stress formula?
- Stress based on instantaneous area. It sits under Stress & Strain, Materials engineering in the EngiRef reference.
- What do the symbols in the True Stress formula mean?
- In True Stress, σₜ is true stress in Pa; σₑ is engineering stress in Pa; εₑ is engineering strain.
- When does the True Stress formula apply?
- True Stress holds under this condition: Uniform deformation before necking; constant volume assumption.