3-point-bending of composite sandwich structure

Julian_R
Julian_R Altair Community Member
edited February 2 in Community Q&A

 

Hello guys,

we conducted a 3-point-bending test of a composite sandwich panel in university. We used a 10mm Rohacell foam core and 2 sheets of CFRP (3 layers each).

I tried to model it in Hypermesh to compare the results. In the real test, we got a deflection of 6,4 mm by an applied force of 2000N.

In my Hypermesh model we got a deflection of 332mm which seems unlikely. Can someone take a closer look at the file and tell me what is wrong?

 

Thank you!

 

 

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Answers

  • Koushik Chandrashekhar_21806
    Koushik Chandrashekhar_21806
    Altair Employee
    edited January 2020

    Hi Julian,

     

    I have just checked your model.

    It looks like the Rohacell core material is extremely light.

    You have given young's modulus of just 70 Pa to it which is very less.

    I gave the E value as 7000 and G value as 1900 and ran the analysis.

    And, i got the following result which is satisfactory. 

     

    <?xml version="1.0" encoding="UTF-8"?>3 point bending.PNG

  • Julian_R
    Julian_R Altair Community Member
    edited February 2020

    Hello Koushik,

    thank you for your quick answer. So the material properties like E and G in an isotropic Mat1 card are expressed in Pascal and not Megapascal like you shown me.

    But how is it in an Mat8 card for an orthotropic material? I put the values in the file I attached to my previous post for my carbon fibre laminate in Megapascals as you can see.

    Is it right or do I need to change the values too, like for the Rohacell foam core in the Mat1 card?

     

    Thank you!

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