FEM ConstraintInitialTemperature

Description

Defines an initial temperature for a thermo-mechanical analysis.

introduced in 1.0: May also be used to prescribe a temperature field in a static analysis step (to simulate thermal expansion with no need for thermomechanical analysis with temperature boundary condition).

Two cubes with different initial temperatures exchanging heat

Usage

1. There are several ways to invoke the command:
   • Press the Initial Temperature button.
   • Select the Model → Thermal Boundary Conditions and Loads → Initial Temperature option from the menu.
2. Enter an initial temperature value for the analysis.

Limitations

1.0 and below: This tool applies the initial temperature to all nodes in the FEA model - it's not possible to select individual regions.

Properties

• Datainitial Temperature: Initial temperature magnitude.
• DataReferences - introduced in 1.1: Regions to which the initial temperature is applied.
• DataEnable Final Temperature - introduced in 1.1: Enabled prescribed temperature field in a static analysis step.
• DataFinal Temperature - introduced in 1.1: Value of a prescribed temperature field in a static analysis step.
• DataEnable Amplitude - introduced in 1.1: Enables the use of CalculiX's amplitude for time variation of the prescribed temperature field. At a given time, magnitude of the field is multiplied by the amplitude value corresponding to that time. Linear interpolation is used between the specified values. Constant values are used outside of the specified range.
• DataAmplitude Values - introduced in 1.1: Amplitude table in the following format:

time_1, amplitude_value_1
…

Notes

• This tool uses the *INITIAL CONDITIONS card in CalculiX.
• introduced in 1.1: The final temperature option uses the *TEMPERATURE card in CalculiX.
• Initial temperature has to be defined for all thermomechanical analyses performed with CalculiX, even the steady-state ones.