Creating an FMU from Surrogates

In Design Manager, you generate the surrogates using a sweep design study, and then export them to Functional Mockup Units (FMUs).

If you are not certain about the range of input parameters required by the external software application, allow large margins for safety so that you avoid passing any invalid data into the external simulation.

Pre-requisite: Before running a sweep study, set up the reference simulation as instructed in Setting Up the Reference Simulation.

  1. To create a Sweep design study, right-click on the Design Studies node and select New.
    The default Study Type for any new design study is Sweep.

    Surrogates can be computed from any study type except CAD Robustness study type.

  2. For each input quantity required by the FMU, add an input parameter in the design study. For details, see Setting Up a Design Study.
    You are advised to add and set the input parameters one by one according to the numbered order of the input variables expected by the external software application. The FMU model can fail to run in the external application if the order of parameters differs from what the external application expects.
  3. For each output quantity required by the FMU, add a corresponding response in the design study. For details, see Setting Up a Design Study.
    Make sure that the order in which you add the responses matches the numbered order expected by the external application.
  4. For each of the responses, create a corresponding surrogate:
    1. Right-click the Design Studies > [design study] > Surrogates node and select New Surrogate.


    2. Select the Surrogates > [surrogate] node and set the relevant Response and other properties.
      For more details of the properties, refer to Surrogate Properties.

      Alternatively, you can also create a surrogate for a certain response by right-clicking the [design study] > Responses > [response] node and selecting Create Surrogate.



    3. Select the Surrogates node to ensure Auto Compute is activated.
    4. (Optional) To enable multi-editing of the created surrogates, right-click the Surrogates node and selecting Edit Surrogate .
      The Surrogate Table is opened up for editing. See also: Edit Surrogates.
  5. To run the design study, right-click the Design Studies > [design study] node and select Run Study.
    NoteThe surrogate computation is done at the end of the study run.
  6. To export the computed surrogates in a FMU file, right-click Surrogates node and select Export to FMU....
    For more details regarding FMU export, refer to Export to FMU....

For a real industrial example of using FMU as sub-model in Simcenter Amesim, refer to Surrogate FMU: Flapper Valve Representation within Simcenter Amesim.