Composite Wing Midplane FEM

[RickAmo]

Hi, im wondering how to make a model of a complete composite wing, with "C" spar, and their skin by midplane analysis. To be more precise, the distance between the spar and skin midplane was 1cm (first aproximate), and i cant figure how to transfer loads/displacements from one to another.
Should i neglect that distance as an aproximation?
The chord is 0,80m and max tickness 13cm (0,13m)
I have access to Femap/Nastran.
Thanks in advance
Rick

 

[GregLocock]

use offsets

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[RickAmo]

yes, i think about that, but i cant figure out how an offset can transfer boundary conditions between layers(skin/Cspar).
to much wondering.
Thanks Greg for rapid response.
Rick

 

[RickAmo]

in adition, if i make 1 surface cant define for it 2 properties, one with positive offset (skin) and another with negative(Cspar cap)
Rick

 

[GregLocock]

No, I don't think so.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[GBor]

Why are you trying to do this with a mid-plane model? I can only think of one possible way, but it would be marginal at best...it would require the use of a "sandwich" composite and defining the core very loosely?

Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.

http://www.borowskiengineering.com

 

[RickAmo]

today i find the way offsets can help me.
Thanks to GregLocock an GBor for the asistance.