Hakki Equation Calculator

Introduction

The Hakki Equation is a material science formula used to calculate the yield strength of materials under strain. It's particularly useful for modeling materials that exhibit strain hardening behavior.

How to Use the Calculator

1. Enter the Initial Yield Strength (σ₀) in MPa. This is the yield strength of the material at zero strain.
2. Enter the Hardening Coefficient (k) in MPa. This coefficient determines how much the yield strength increases with strain.
3. Enter the Strain (ε). Strain is a measure of deformation representing the displacement between particles in the material body relative to a reference length.
4. Enter the Strain Hardening Exponent (p). This exponent determines the rate at which the yield strength increases with strain.
5. Click the Calculate button to compute the yield strength.
6. Use the Reset button to clear all input fields and start over.

Principle Explanation

The Hakki Equation models the relationship between yield strength and strain in materials that exhibit strain hardening. The equation assumes that the yield strength increases linearly with strain when plotted on a log-log scale.

Example

For example, if a material has an initial yield strength of 200 MPa, a hardening coefficient of 150 MPa, a strain of 0.05, and a strain hardening exponent of 0.3, the yield strength at that strain would be:

σ_y = 200 + 150·(0.05)^0.3 ≈ 211.45 MPa