II.1.11.1 Material thermal parameters

Two scalar parameters influence the transient thermal behavior of laminates: the density $\rho$ and the heat capacity (per unit of mass) $C_p$. As these two parameters are scalar, their characteristics do not depend on the possible anisotropy of the material.

On the other hand, the thermal conductivity ${\lambda }^T$ is a $2^{\text{nd}}$ order tensor. Generally, for an anisotropic material, the thermal conductivity equation can be written as follows:

For an orthotropic material, the previous equation reduces to:

Then, only three material parameters define the thermal conductivity. Finally, for an isotropic material the thermal conductivity is defined by a single parameter ${\lambda }^T$: