Simple Stress Relaxation Calculator

A simplified illustration of stress relaxation under imposed strain, using a secondary creep law to estimate the stress decline. Illustrative only.

Creep & High-Temperature3 min read

calculatorstress relaxationimposed straincreepillustration

Calculator

For small increments, stress relaxation rate:
  d(sigma)/dt = -E * A * sigma^n * exp(-Q/(R*T))

where:
  sigma = current stress [MPa]
  E = elastic modulus at temperature [MPa]
  A, n, Q = Norton parameters
  R = 8.314 J/(mol*K)
  T = absolute temperature [K]

This is a simplified illustration. For accurate
relaxation, use FEA with a creep model that captures
the full strain-time response.

Assumptions

Total strain is constant (imposed displacement)
Secondary creep only (no primary or tertiary)
Small stress change per increment (linearised)
Temperature is constant

Limitations

This calculator is a simplified illustration only. It uses a linearised approximation of the relaxation ODE and does not capture primary creep, stress-dependent modulus, or temperature changes. For engineering assessments, use FEA with a properly calibrated creep model.