Use the Thermal Expansion subnode to add an internal thermal strain caused by changes in temperature.

From the Temperature T list, select an existing temperature variable from another physics interface, if any such temperature variables exist, or select User defined to enter a value or expression for the temperature.

Select an Input type to select how the thermal strain is specified. The default is Secant coefficient of thermal expansion, in which case the thermal strain is given by

where α is the secant coefficient of thermal expansion. α can be temperature dependent.

When Input type is Tangent coefficient of thermal expansion, the thermal strain is given by

where αt is the tangential coefficient of thermal expansion.

When Input type is Thermal strain, enter the thermal strain dL as function of temperature explicitly.

In all three cases, the default is to take values From material. Use User defined to enter an expression for the coefficient of thermal expansion or thermal strain.

Enter a value or expression for the Strain reference temperature Tref which is the reference temperature that defines the change in temperature together with the actual temperature.

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