Thermal Expansion (for Materials)
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
It is possible to model bending due to a temperature gradient in the transverse directions of the beam. The temperature is then assumed to vary linearly through the thickness.
Model Inputs
The Volume reference temperature Tref is the temperature at which there are no thermal strains. As a default, the value is obtained from a Common model input. You can also select User defined to enter a value or expression for the temperature locally.
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.
See also
•
Using Common Model Input
•
Default Model Inputs and Model Input in the COMSOL Multiphysics Reference Guide.
Thermal Expansion Properties
Specify the thermal properties that define the thermal strain.
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.
Thermal Bending
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.
Location in User Interface
Context Menus
Beam>Linear Elastic Material>Thermal Expansion
Ribbon
Physics tab with Linear Elastic Material node selected in the model tree:
Attributes>Thermal Expansion