Use the Thermal Expansion subnode to add an internal thermal strain caused by changes in temperature. The thermal strain depends on the coefficient of thermal expansion (CTE) α, the temperature T, and the strain-free reference temperature Tref as

From the Temperature T list, select an existing temperature variable from a heat transfer interface. For User defined enter a value or expression for the temperature (the default is 293.15 K). This is the centerline temperature of the beam, controlling the axial part of the thermal expansion.

From the Coefficient of thermal expansion α list, select From material to use the coefficient of thermal expansion from the material, or User defined to enter a value or expression for α.

Enter a value or expression of the Strain reference temperature Tref, which is the reference temperature where the thermal strain is zero.

Enter the Temperature gradient in local y-direction Tgy (in 2D and 3D) and in the Temperature gradient in local z-direction Tgz (in 3D), which affects the thermal bending. If beam cross section dimensions have been defined at Bending stress evaluation points—From section heights, these could be used in an expression containing the temperature difference.

Physics tab with Linear Elastic Material node selected in the model tree:
Attributes>Thermal Expansion