Modelica Multibody with fluidon library: connection element mismatch

arnigaber
arnigaber Altair Community Member
edited October 2020 in Community Q&A

Hello to all!

I found this error connecting modelica's element of my spring damper system with the multibody element of modelica.

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Which connector should i use? 

My aim is to simulate a free fall mass with a spring and a hydraulic damping system. I found this element in th demo file SpringDamperSystem.

Thank for the attention.

Arnigaber

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Answers

  • RoKet
    RoKet
    Altair Employee
    edited April 2020

    Hi Arnigaber,

    There is a small difference between your model and the demo SpringDamperSystem. In the demo all mechanical components are taken from Multibody library, you can recognize it by the connectors.

    grafik.png

    You can't combine Multibody connectors and Translational connectors directly as the direction of Translational isn't defined in space. In that case you have to use a Multibody component that allows the insert of a Translational element, e. g. LineForceWithMass or JointUPS.

    grafik.png

    Alternatively you can setup your model as a pure 1D system. Replace the world by fixed, and add the gravitation force separately (or use Inclination angle in cylinder).

    The demo LandingGear in HydraulicsByFluidon/CoSim shows an example of a passive hydraulic damper, also Monotube damper and Twin-tube damper in HydraulicsByFluidon/CircuitModels.

  • arnigaber
    arnigaber Altair Community Member
    edited April 2020

    Thanks RoKet!

    As always very helpful!

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