Materials are considered to be orthotropic if the properties depend on the direction. To properly use an orthotropic material, the material axes must be defined in the Element Definition dialog. All the thermal element types except for rods support orthotropic materials. The orthotropic material properties are listed below. Depending on the analysis type, not all the material properties may be required. It may also be necessary to define some Isotropic Material Properties.
When using temperature dependent material properties, also see the page Temperature Dependent Material Properties for information.
Thermal conductivity in the n (or r) direction (K r or K n ):
The thermal conductivity of a material in the n (or r) direction is a measure of the ability of the material to conduct heat in that direction. A material with a high thermal conductivity will conduct heat better than a material with a low thermal conductivity. The n direction is used for thermal plate elements. The r direction is used for all other thermal elements that support orthotropic materials. This property is required for all thermal analyses. See the appropriate page in Element Types and Parameters for information on how to define the material axes.
Thermal conductivity in the s direction (K s ):
The thermal conductivity of a material in the s direction is a measure of the ability of the material to conduct heat in that direction. A material with a high thermal conductivity will conduct heat better than a material with a low thermal conductivity. This property is applicable for all thermal elements that support orthotropic materials. This property is required for all thermal analyses. See the appropriate page in Element Types and Parameters for information on how to define the material axes.
Thermal conductivity in the t direction (K t ):
The thermal conductivity of a material in the t direction is a measure of the ability of the material to conduct heat in that direction. A material with a high thermal conductivity will conduct heat better than a material with a low thermal conductivity. This property is applicable for all thermal elements that support orthotropic materials except for 2D elements. This property is required for all thermal analyses. See the appropriate page in Element Types and Parameters for information on how to define the material axes.
Specific heat:
The specific heat of a material is the amount of energy required to raise the temperature of a single unit of mass of the material 1 degree. This property is applicable to all thermal elements and is required for a transient heat transfer analysis. The specific heat does not affect the results for steady-state thermal analyses.