Honeycomb modeling with shell elements

Staedtlerp

Good morning all,

 

I'm modeling a composite laminate made of carbon fiber layers and honeycomb.

I'm modeling using the pshell elements and MAT8 card. The question is that I don't really know how to fill the material card entries.

I'm using Nomex honeycomb and the properties provided by the supplier are those depicted in the attached photo.

Using MAT8 I need 9 mechanical properties (E1, E2, NU12, G12, Xt, Yt, Xc, Yc, and S, excluding density) but I haven't got these properties and I don't know how to insert the properties provided by the supplier's datasheet.

 

Can anyone help me??

 

Thank you very much

 

 

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Altair Forum User

Hi Staedtlerp,

 

Can you share the reference, from where you got this data?

 

 

Thank you

Staedtlerp

Hi Premenand,

thank you for your reply.

 

yes sure, below you can find the document downloaded directly from Hexcel supplier's site.

 

Thank you

Unable to find an attachment - read this blog

Altair Forum User

I generally model Nomex honeycomb in the same way, and would make this MAT8 card for that core:

 

 MAT8           1     1.0     1.0     0.3      1.0   41.0    20.0  3.2-11                                      1.0      1.0    1.0     1.0    0.35

EDIT: You can put the real strengths in if you like, but generally I just use 1MPa since I don't check the failure of the core within my FEM analysis. I use 1.0 for E11 and E22 since the honeycomb doesn't carry load in these directions - the skins do.

 

Staedtlerp

Great!!/emoticons/default_biggrin.png' srcset='/emoticons/biggrin@2x.png 2x' title=':D' width='20' />

 

Thank you very much for your help.

 

I'll put the values and I'll let you know.

 

Thanks gain

Altair Forum User

Hi @Staedtlerp

Is there a reason for modeling honeycomb with the shell?

 

The std practice is to model with solid elements. but if you have a very large honeycomb cell size, shells can be used effectively as long as you are not resin filled.  If your core is a significant thickness in the total composite, it would be more appropriate to use a solid representation anyway rather than assuming it is a 'layer' in a composite PCOMP

Altair Forum User

It depends on the model and the part. For example we don't use solid elements in GFEMs of whole aircraft models in the aerospace industry.

Altair Forum User

Altair Forum User said:

It depends on the model and the part. For example we don't use solid elements in GFEMs of whole aircraft models in the aerospace industry.

Yes, because of their large size.