How to Calculate Thermal Expansion
What is Thermal Expansion?
Thermal expansion describes how materials change size with temperature. Most solids expand when heated and contract when cooled. Linear thermal expansion: ΔL = α × L₀ × ΔT, where α is the material's coefficient of thermal expansion.
Step-by-Step Guide
- 1Linear expansion: ΔL = α × L₀ × ΔT
- 2Volumetric expansion: ΔV = β × V₀ × ΔT ≈ 3α × V₀ × ΔT
- 3α (steel) ≈ 12 × 10⁻⁶ /°C · α (aluminium) ≈ 23 × 10⁻⁶ /°C · α (concrete) ≈ 12 × 10⁻⁶ /°C
Worked Examples
Input
Steel rail 10m long · temperature rise 50°C
Result
ΔL = 6mm
12×10⁻⁶ × 10 × 50 = 0.006m