5.15.21.5. Understanding Behavior in Terms of Solver Inputs

This section describes the effect of some of the above parameters on the commands that are input to the solver.

Weld Heat Input

The following behavior only applies to Transient Thermal analysis:

  • Temperature: For this option, D,ALL,TEMP,%Temperature value% is supplied to the weld selection.

  • Power - Direct: For this option, BFE,ALL,HGEN,,%DirectHeatGenerationValue% is supplied to the weld selection.

  • Power - Indirect: For this option, the total power is calculated as the product of Machine Constant, Voltage and Current. This is then divided by the volume of the weld selection and this value is applied as BFE,ALL,HGEN,,%CalculatedValue%.

Ambient Temperature

The specified value is used in a Static Structural analysis to define the ambient temperature. BF,ALL,TEMP,%AmbientTemperature% is used in the solver.

Weld Mode

Two mode options are available:

  • Material Deposition: adds ekill and ealive commands to the solver and is executed according to the weld selections.

  • Direct Energy Deposition: applies load without ekill and ealive commands to the solver and is executed according to the weld selections.

Thermal Strain Scaling Factor

This factor can be used to account for unknown effects in your simulation that may affect the final welded bodies' distortion or stress state, for example, thermal boundary conditions (which directly affect temperature distribution) or temperature dependent material properties. It can also be used to account for the simplifications made when using a structural standalone analysis.

The thermal deformation of a structural body is calculated as follows:

where is the thermal deformation and is the scaling factor.

By modifying the Reference Temperature of a specific body, you can select at which temperature the bodies are in a non-deformed state in the simulation.

For example, if is defined as the initial temperature when the bodies are activated, the initial thermal strain of those bodies would be equal to zero. This will therefore achieve the maximum volumetric shrinkage when the bodies are cooled down to room temperature.