why does penetration occur?

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

Hi,

 

I want to know the reason why penetration occurs.

auto1 :  Length (x-direction) = 1000, Height = 100(y-direction),  mesh size = 50

component1(yellow) : same as auto1.

 

When I make component1, I use 'translate -> duplicate-> y-direction -100'.

 

If I assign Property and Material on the components,  Penetrations occurs.

(If property and material are not assigned, penetrations does not occurs.)

 

Why does it happen??

 

Thanks.

 

 

image.png.c2a58d5f9da8a06c623001949c1c8756.pngimage.png.c4db0587e095b436937720dd9a6c1e8b.png

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited July 2019

    Hi,

     

    the penetration is detected after assigning property with thickness value defined. This is due to the way the Minimum gap for impact activation (Gapmin) is computed if not specified.

     

     

    If Gapmin=0 or blank, a default value is computed as:

    If master segments are shell and solid elements, Gapmin = min ( tm , lmin2lmin2 ).

    Where,
    tm
    The average thickness of the master shell elements, for Igap=0
    tm
    The minimum thickness of the master shell elements, for Igap=1, 2, or 3
    lmin
    The smallest side length of all master segments (shell or brick)

    If master segments are all solid elements Gapmin = lmin10lmin10

    Where, lmin being the smallest side of all master brick segments.

     

     

     

    If no thickness is provided the penetration checker will fail to detect penetrations as tm is not available. This isn't a real issue anyway since the model will not be able to run without material and property properly defined.

     

    For more details refer to the attached document from Radioss Help.
     

    Unable to find an attachment - read this blog