Defining thermal expansion

You can define thermal expansion either by entering thermal expansion coefficients in the Edit Material dialog box or, if the thermal strains are complicated functions of field and state variables, with user subroutine UEXPAN. See Thermal Expansion, for more information.

  1. From the menu bar in the Edit Material dialog box, select MechanicalExpansion.

    (For information on displaying the Edit Material dialog box, see Creating or editing a material.)

  2. Click the arrow to the right of the Type field, and specify the directional dependence of the thermal expansion.
  3. Toggle on Use user subroutine UEXPAN if you want to define the increments of thermal strain in user subroutine UEXPAN.
  4. If you toggled on Use user subroutine UEXPAN, click OK to create the material and to close the Edit Material dialog box. Alternatively, you can select another material behavior to define from the menus in the Edit Material dialog box (see Browsing and modifying material behaviors for more information).

    If you choose to specify thermal expansion coefficients directly in the Edit Material dialog box, perform the remaining steps in this procedure.

  5. If the thermal expansion is temperature- or field-variable-dependent, enter a value for the Reference temperature, θ0.
  6. Toggle on Use temperature-dependent data to define data that depend on temperature.

    A column labeled Temp appears in the Data table.

  7. Click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables on which the data depend.
  8. Enter the applicable data in the Data table:

    Expansion Coeff alpha

    Isotropic thermal expansion coefficient, α. (Units of θ−1.)

    alpha11, alpha22, and alpha33

    Three values to define orthotropic thermal expansion, α11, α22, and α33. (Units of θ−1.)

    alpha11, alpha22, alpha33, alpha12, alpha13, and alpha23

    Six values to define anisotropic thermal expansion, α11, α22, α33, α12, α13, and α23. (Units of θ−1.)

    Temp

    Temperature.

    Field n

    Predefined field variables.

    You may need to expand the dialog box to see all the columns in the Data table. For detailed information on how to enter data, see Entering tabular data.

  9. Click OK to create the material and to close the Edit Material dialog box. Alternatively, you can select another material behavior to define from the menus in the Edit Material dialog box (see Browsing and modifying material behaviors, for more information).