Node Deactivated from Interface - Error

Naresh
Naresh Altair Community Member
edited April 2 in Community Q&A

Hello All,

Any idea how can I ask Radioss to avoid/neglect this node from contact and proceed the simulation.  Few nodes of the foam deform a lot and believe causing this error. I am ok to neglect this after so much of deformation and proceed the simulation. By the way interface 100 is TYPE7 contact.

Mostly used default setting for most of the TYPE7 contact parameters.

image

Screen grab of the Contact parameter.

image

Regards,

Naresh Kini

 

Answers

  • Polyvios Romanidis
    Polyvios Romanidis New Altair Community Member
    edited March 27

    Hi Naresh,

    The set up you made for the TYPE7 Interface is the recommended one.  Additionally, your simulation have run for almost 800000 cycles before break, so I think is a proper set up.

    At the point you sent the screenshot, your model have already exploded and that can be caused for different reasons.  So, more information needed to examine what went wrong!

    What contact exactly you are trying to simulate with this set up?  Is it a self contact?

    Are you using Advanced Mass Scaling (AMS) Method for your solution?  This method can make your simulation run faster but sometimes can make the model unstable.

    Is it possible to share your model and the .out files to examine any possible mistakes made in set up or causes for this problem?

    Polyvios

  • Naresh
    Naresh Altair Community Member
    edited March 27

    Hello Polyvios,

    Thanks for the quick reply. Its a structural loadcase with mix of ATD, Cushion and Aluminum structure. This is causing due to hour-glassing or excess deformation of the cushion. I am not using AMS in my model. Just using node based mass scaling.

    This is a TYPE7 contact. Used as a surrogate for single surface or self contact. 

    I know the cause of the issue, just try to know, if I get a option in CONTACT to neglect or delete this distorted element and proceed instead of not having anything due to 1 node of deformed cushion. 

    I am afraid I can share the model at this stage.

    Regards,

    Naresh Kini

  • Polyvios Romanidis
    Polyvios Romanidis New Altair Community Member
    edited April 2

    Hello Polyvios,

    Thanks for the quick reply. Its a structural loadcase with mix of ATD, Cushion and Aluminum structure. This is causing due to hour-glassing or excess deformation of the cushion. I am not using AMS in my model. Just using node based mass scaling.

    This is a TYPE7 contact. Used as a surrogate for single surface or self contact. 

    I know the cause of the issue, just try to know, if I get a option in CONTACT to neglect or delete this distorted element and proceed instead of not having anything due to 1 node of deformed cushion. 

    I am afraid I can share the model at this stage.

    Regards,

    Naresh Kini

    Hi Naresh,

    You can try different things in order to achieve what you asking for.

    One way could be to introduce a failure model (probably /FAIL/JOHNSON) and let Idel=2, so the distracted element can be deactivated and the solution can continue normally.

    Additionally, you can use /DT/INTER/DEL and set a minimum time step at least 10 times smaller than the normal time step in your simulation!

    Finally, if you think that the problem is because of hourglass and you use version 2023.1, you can try the recently introduced Isolid = 5 formulation!

    Polyvios