• From: Zagreb, Croatia
  • Registered: 05-02-2019
  • Posts: 11

Topic: Surface loads on mitc4shell element

Can surface loads (ConstantSurfaceLoad) be applied on mitc4shell elements? In the OOFEM Element Library Manual it says that both body and boundary loads are supported for mitc4shell element. However, I haven't managed to make it work (input file is attached). Based on the output file (the response is zero), it seems that it simply remains unloaded. As far as I understand from the previous posts, no "faces" or "boundaries" should be specified for this type of element - just a set of elements to be loaded should be related to the ConstantSurfaceLoad.

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mitc4shell-load-surface.in 1006 b, 3 downloads since 2019-05-30 

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2 Reply by bp

  • bp
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  • From: Prague, Czech Rep.
  • Registered: 02-03-2007
  • Posts: 1,026

Re: Surface loads on mitc4shell element

Hi Marin,
Please find attached the corrected input, I did not checked but it seems to work. You have to apply surface load to element surfaces, defined using elementboundaries keyword in a set.
Borek

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mitc4shell-load-surface.in 1.03 kb, 11 downloads since 2019-07-17 

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  • From: Zagreb, Croatia
  • Registered: 05-02-2019
  • Posts: 11

Re: Surface loads on mitc4shell element

Dear Borek,
based on the file from your reply, it seems to me that the convention for definition of entries in 'elementboundaries' set is as follows: face ID, element ID (global number). However, when I go through OOFEM code, it seems that the convention is just opposite. I attach a print screen with a part of 'assembleVectorFromBC' method of 'EngngModel' class. If the convention from the file were valid, I would expect the arguments in 'at' method of 'IntArray' class in lines 1171 and 1174 to be switched.
I would like to hear your thoughts on this because we are currently finishing implementation of a new shell finite element and have to provide support for ConstantSurfaceLoad so I have to know if this is a bug that needs to be fixed or the convention from the file is wrong.
Thanks,
Marin

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  • Registered: 25-06-2013
  • Posts: 241

Re: Surface loads on mitc4shell element

Hi Marin, You are right, the convention is element Id, face Id.

  • Registered: 25-06-2013
  • Posts: 241

Re: Surface loads on mitc4shell element

Hi Marin, You are right, the convention is element Id, face Id.

  • From: Zagreb, Croatia
  • Registered: 05-02-2019
  • Posts: 11

Re: Surface loads on mitc4shell element

Thanks, Martin!