Thermal Expansion of a Component
Thermal Expansion of a Component
Temperature swings make parts grow and shrink. Ignoring it leads to seized fits, buckled rails and leaking joints.
The free thermal expansion is ΔL = α·L·ΔT. where α is the coefficient of thermal expansion, L the original length and ΔT the temperature change.
Inputs
alpha := 12e-6 K^-1=1.2e-05 1/K
L := 10 m=10 m
dT := 40 K=40 K
Multiply the coefficient, length and temperature change.
dL := alpha·L·dT=4.8 mm
Results
Even a 40 K rise moves a 10 m steel member several millimetres — enough to demand expansion joints or sliding bearings. Restrained expansion instead builds up large thermal stresses.
Assumptions & limitations
- Free (unrestrained) expansion.
- Constant expansion coefficient over the range.
- Uniform temperature change.