AMS

Yuvarajs91
Yuvarajs91 New Altair Community Member
edited October 2020 in Community Q&A

Hello,

 

I have used P3-Beam with Rigid body to represent the bolt (Refer Attached Image) where the beam is connected with rigidbody master node.

Radioss shows error in Radioss2017 but not in Radioss13. I have no issue in Radioss2017 without AMS.

Please clarify how the run the same simulation in Radioss2017 with AMS.

 

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image.png.d9fa38e4b616830c7bcaa9e808d713a8.png

 

Thanks and Regards,

Yuvaraj

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2018

    Hi Yuvaraj,

    It is not recommended to set a node of the mesh as the master node of a rigid body as depending on the flag ICoG, which is used in the rigid body definition, a lot of mass and inertia can be added locally onto the node; as well as the node can be moved to the center of mass of the rigid body.  Accidentally it might have ran in 13 version as this is not recommended.

    Please try this workaround:

    Import the file in HyperCrash. Run the model checker (Quality>>Model Checker).

    An error will be displayed that RBODY master on element.

    1.PNG

     

     

    Select the error, right click and select run so that it will adjust internally the node position.

    Now export the file and try running.

     

    2.PNG

  • Yuvarajs91
    Yuvarajs91 New Altair Community Member
    edited March 2018

    Hello George,

     

    Thanks for the reply. I can able to run the simulation in Radioss2017 if I fixed the master node on element.

     

    I am using following AMS cards in Engine file. In Radioss14.0 and Radioss13 which is solving very quickly.

    But in Radioss2017 the same deck file is taking 5 time solving time of Radioss14.0 and Radioss13. 

     

    image.png.3884ee2d0ca90cc83b75d2c1edaf823c.png

     

    Minimum Time step in AMS card = 10 time of minimum timestep in Deck file=(10*12e-5)=12e-4

    Please clarify the time variation in Radioss2017. Do I need to change anything in AMS card, Is AMS recommended?

    If possible please give some guidance for AMS. 

     

    Thanks and Regards,

    Yuvaraj

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited March 2018

    Hi Yuvaraj,

    Let us know what kind of analysis you are running. Like is it a crash, or quasi static case.

    Normally for any targeted model for AMS application should run first in /DT/NODA/CST with an acceptable added mass (MAS.ER < 0.02) along its simulation time. For this time step chosen for /DT/NODA/CST, user can choose the new time step for /AMS which 10-20 times. 

    Normally for 2017 it should run much effectively than the older versions. 

     

     

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