Young's Modulus Calculator Formula

Understand the math behind the young's modulus calculator. Each variable explained with a worked example.

Formulas Used

Young's Modulus

modulus_mpa = stress_val / strain_val

Young's Modulus

modulus_gpa = stress_val / strain_val / 1000

Variables

VariableDescriptionDefault
stress_valApplied Stress(MPa)200
strain_valMeasured Strain(mm/mm)0.001

How It Works

Young's Modulus (Elastic Modulus)

Young's modulus quantifies material stiffness in the linear elastic region.

Formula

E = sigma / epsilon

where sigma is the applied stress and epsilon is the resulting strain. E is measured from the initial linear portion of a tensile test stress-strain curve. Typical values: steel 200 GPa, aluminium 70 GPa, concrete 25-35 GPa, timber 8-14 GPa.

Worked Example

A tensile test specimen shows 200 MPa stress at 0.001 strain.

stress_val = 200strain_val = 0.001
  1. 01E = 200 / 0.001 = 200,000 MPa
  2. 02E = 200,000 / 1000 = 200 GPa
  3. 03This matches structural steel, confirming the specimen is steel.

Frequently Asked Questions

What is a typical Young's modulus for steel?

Structural steel has E approximately equal to 200 GPa (29,000 ksi) regardless of grade. Higher-strength steels are stiffer in strength but have the same elastic modulus.

How is strain measured in practice?

Strain is measured using strain gauges (electrical resistance), extensometers (mechanical clip-on devices), or digital image correlation (DIC) for full-field measurements.

Does temperature affect Young's modulus?

Yes. Most metals soften at elevated temperatures. Steel's modulus drops to about 60% of its room-temperature value at 600 degrees C, which is critical in fire engineering.

Learn More

Guide

Thermal Expansion Guide: Calculating Length, Area, and Volume Changes

Understand thermal expansion in engineering materials. Learn to calculate linear, area, and volumetric expansion, handle expansion joints, and avoid thermal stress failures.

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