FMU only for transient?

Luca Cavagna
Luca Cavagna Altair Community Member
edited March 15 in Community Q&A

Hello gents,

very briefly. I received an error message if I try to run my model with the FMU linked if I choose static+transient.

FMU "AEROPROP" of type "CoSimulation" of  is not supported for Static+Transient analysis. [General]

 

I am wondering if I can disactivate it and write a template to run static and then the transient.

Unfortunately I cannot disactivate it as we usual do with MOTION or FORCE elements.

Cheers

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Best Answer

  • GTT Adam
    GTT Adam
    Altair Employee
    edited March 15 Answer ✓

    Hi Luca,

    Based on that error message I would say you are correct in assuming that you can't run a Static+Transient analysis in Simulink (guessing based on your last post). It would be worthwhile to test the Template method, however I feel you may get the same result as the cosimulation may only allow 1 simulation type.

    Without understanding the model or event you are trying to simulate, I would recommend you create a transient-only simulation such that the vehicle is able to come to rest for a few seconds before ramping on the forces or motions through STEP functions.

     

    Hope this helps!

    Adam Reid

Answers

  • GTT Adam
    GTT Adam
    Altair Employee
    edited March 15 Answer ✓

    Hi Luca,

    Based on that error message I would say you are correct in assuming that you can't run a Static+Transient analysis in Simulink (guessing based on your last post). It would be worthwhile to test the Template method, however I feel you may get the same result as the cosimulation may only allow 1 simulation type.

    Without understanding the model or event you are trying to simulate, I would recommend you create a transient-only simulation such that the vehicle is able to come to rest for a few seconds before ramping on the forces or motions through STEP functions.

     

    Hope this helps!

    Adam Reid

  • Christopher_Fadanelli
    Christopher_Fadanelli
    Altair Employee
    edited March 15

    Hi Luca,

    It looks like you are using MotionView 2021.1. I would suggest updating to the most recent version (2023.1). Going off of Adams post, if you are using Simulink. You can import the Simulink model into Twin Activate. From there you can co-simulate with MotionSolve as an fmu or use the co-simulation blocks in Twin Activate.

     

    Best,

     

    Christopher Fadanelli

    Application Engineer - Multibody Dynamics

    Troy, MI

     

  • Luca Cavagna
    Luca Cavagna Altair Community Member
    edited March 15

    Hello Adam and Chris

    thanks a lot for the reply. Much appreciated.

    Correct Adam: if I use the template method (run a static and then a transient) It seems like there is no complain. I still have to look into carefully step by step.

    Another option is to disactivate aero forces coming from the FMU and switch them on once the aircraft has converged with gears on ground.

    Chris, that was an option but the simulink model is not so simple and the translator failed. Also, since the aero and control model is coming from the stability and control department I would like to use one model and the same model they have (and gets the updates from the repository they manage).

    At the moment it seems like the FMU from Matlab imported in MV/MS works properly.

    Thanks guys for the help!

  • Luca Cavagna
    Luca Cavagna Altair Community Member
    edited March 15

    Adam. Confirmed. Template mode and static run called: no complain. Run

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