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SG

  1. Anonymous

    Dear Professor Yu,

    How to set the length of the red line segment in the figure below, and whether the SG is established by shell element or solid element.

     

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    1. Ning Liu

      Hi,

      Did you upload a figure? I cannot see it from my side

       

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      1. Anonymous

        • Sorry, I don't know why the picture didn't upload successfully.I tried again, but the picture still couldn't be uploaded successfully, so I had to add it in the attachment.  

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    2. Wenbin Yu

      You can use Help->Report a problem to let our IT support folks to figure out the issue why the picture is not shown.

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      Replying to Wenbin Yu

      1. feng liu

        Thank you very much for your reply. I have fed back to the platform according to your method and am waiting for your reply. Can you see the attachment I uploaded? I look forward to your reply.

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    3. Ning Liu

      To answer your question, that 3D SG in your figure specifically is in solid element, the length does not matter, can be arbitrary (even zero).

      With that being said, if the length of such 3D SG becomes zero, it is equivalent to a 2D SG (in shell element), which will give you the same constitutive relations (6x6 plate stiffness). Actually, the 2D SG is the fundamental building block, or a unit cell, that contains all the necessary information for constitutive modeling in this case, the length (your red line) is only required for 3D SG.

      Consider here the 3D SG as an extrusion from 2D SG along your red line,  nothing new.

      However, the 2D SG only works when the stiffeners are uniform in the longitudinal direction, if a cross-type stiffeners are present (stiffeners are pointing both directions), then SG has to be in 3D.

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    4. Wenbin Yu

      For 2D SG, you have 8 as homogenized SG volume
      For 3D SG, you have 32 as homogenized SG volume. 
      Can you explain what are they? 

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    5. Wenbin Yu

      One thing I notice is that for your 3D SG, you have many aperiodic nodes  in y2 direction, which is not correct. Try to make a periodic mesh to correct this mistake first.

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    6. Ning Liu

      Make sure you output your y1-y2 -y3 as follows (y1 and y2 being periodic BC, y3 being the through-thickness direction), that way, SwiftComp should compute the right constitutive relations for you

      Capture.PNG

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      1. Anonymous

        Thank you very much for your reply. I'll practice again.

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