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User-entered CTE

Free thermal expansion

Inputs

Unloaded length at the stated initial temperature.
Signed average CTE over the stated temperature interval. Negative means contraction on heating.
Final minus initial temperature. Positive = heating.

Results

Ideal free length changeΔL

0.936

Ideal final lengthL

1,200.9

Free thermal strainεth

780

ΔL = αL₀ΔT; εth = αΔT

A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.

Nearby: Restrained thermal stress

Method

Formula, when it applies, and when it does not

Calculate ideal free linear length change from a signed coefficient of thermal expansion, initial length, and temperature interval.

ΔL = αL₀ΔT; εth = αΔT

When

  • Free expansion
  • Uniform temperature
  • Signed user-entered CTE
  • Near-constant CTE

Don’t

  • This is ideal free linear expansion using a user-entered signed average CTE; a negative coefficient is contraction on heating. It excludes restraint, temperature gradients, anisotropy, phase change, joints, nonlinear material response, property variation, and thermal-stress or design decisions.
OpenStax thermal-expansion reference