Contact surfaces and shear force

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello everyone,

 

I am currently performing a shear test on a sandwich panel which lies on top of two composite L-shaped side supports as shown below:

 

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Since the L-shaped side supports movement is fully constained, the sandwich panel would be expected to rest on top of them once the vertical load is applied when studying a linear static case. However, when running OptiStruct this is not the case and the sandwich panel just runs through the side supports like they are not even there. I tried creating contact surfaces at both the top of the L-shaped side supports and the bottom of the sandwich panel as well as an interface between them but the sandwich panel is still 'pushed down' and not sustained by the supports when running the analysis. Images below show Frames 0 and 1 from HyperView results; note how the sandwich panel just disappears down the screen while the side supports remain untouched.

 

<?xml version="1.0" encoding="UTF-8"?>image.thumb.png.7d682b30a4c0b136c9f8e25f341e7ac3.png

 

<?xml version="1.0" encoding="UTF-8"?>image.thumb.png.f0bd1caaf8f5160a82298dfc24b0259b.png

 

Any ideas on how to fix this issue? 

 

Thanks a lot in advance.

 

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited February 2019

    Hi,

     

    I have made the following changes in order to make the contact work:

    -the upper contact surface normals were reversed by analysis>contactsurfs>adjust normals

    -contact type was changed to FREEZE

    -SRCHDIS was set to 25

     

    Note however for linear static analysis the contact status does not change and the contact stiffness is constant throughout.

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  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2019

    Just what I was asking for! THANK YOU very much Ivan!