Engineering calculator

Diffusion Calculator

Estimate moisture uptake through the thickness of a flat thermoset composite laminate with both broad faces exposed.

Enter conditions

Use a diffusion coefficient measured at the relevant temperature and humidity.

Laminate thickness

Diffusion coefficient (D)

Exposure time

Optional mass estimate

Equilibrium moisture content

% dry mass

Initial dry mass

Estimated uptake

Predicted average moisture across the laminate.

8.7%of equilibrium uptake

Moisture content0.131%of dry mass

Water gained0.1311 gestimated

Conditioned mass100.1311 gdry mass + water

ModelM_t / M_∞ = 1 − 8/π² Σ [1/(2m+1)²] e^{−(2m+1)²π²Dt/L²}

Assumptions

One-dimensional Fickian diffusion through a uniform, initially dry flat laminate; both broad faces exposed; edges effectively sealed; constant diffusion coefficient and exposure conditions; no swelling, cracking, or chemical change.