Defining Moving Heat Fluxes

You can specify the laser and heat energy parameters that control how the heat used in additive manufacturing is distributed.

The steps below are based on use of the default (Built-in) schema for moving heat fluxes that is embedded in the app. Step 3 allows you to use a custom schema instead. A custom schema redefines the interface (dialog box) to work with a user subroutine that exposes only the options required for your process. In this case, your moving heat flux options might be different from those described.

Before you begin: To understand the entries and definitions required, review the Abaqus user subroutines and keywords for use with additive manufacturing.

Moving heat flux is tied to the UMDFLUX user subroutine.

See Also
About Moving Heat Flux
In Other Guides
About Additive Manufacturing Process Simulation
  1. From the Additive Manufacturing section of the action bar, click Moving Heat Flux .
  2. Select the part.

    The part indicates the predefined volume (part or mesh) that is filled with material, layer by layer, to become a real part as the additive manufacturing process is completed.

  3. Optional: Add a Custom definition to choose a schema that redefines the entries in the dialog box to match your additive manufacturing process.

    You can either open an existing schema from the current session or import a saved schema file. The default material input schema is shown as the example in About XML Schema Files.

    The dialog box is reconfigured to match the schema entries.
  4. Depending on the source of the product information, you have options when assigning the Laser Event Series that describes the motion and power of the laser.
    • For a simulation using data from the Powder Bed Fabrication app, the Laser Event Series is selected automatically. However you can override this Laser Event Series with an external document.
    • For a simulation not using data from Powder Bed Fabrication, select a document containing the material deposition Laser Event Series.

    An event series contains time, X-, Y-, Z-, and one additional data field to simulate the position and motion of the laser that heats the deposited material to bond it with the previous layers.

  5. Choose an Energy Distribution.
    • Concentrated
    • Uniform
    • Goldak

    The formats are standard for additive manufacturing and describe how heat energy is managed within the range of influence of the laser.

  6. Choose whether energy is conserved.
  7. Select Absolute or Relative offset motion for the laser.

    Motion type is for use with the offset values (Uniform distribution). Absolute uses the offset values directly. Relative uses the offset values as a percentage of the corresponding box length values.

  8. Enter the laser X-, Y-, and Z-vectors to define the laser motion.
  9. Edit the heat absorption coefficient data in the table.

    The flux absorption coefficient must be between 0 and 1; it defines the percentage of power from the heat source that is absorbed by the part.

    You can include temperature dependence.

    Tip: You can either enter the data directly or right-click a cell to import data.