Is it possible to represent a composite sandwich panel made of 2 carbon fiber plies (one on each side of the core) and nomex honeycomb (core) as a single MAT9OR material?

Hi,

I am a student in mechanical engineering and I want to run FEA on composite sandwich to analyze bending behaviour of certain parts.

As stated in the question, the sandwich construction is as follows:

1. Cross-ply carbon fiber lamina [0/90]

2. 4.8 mm Honeycomb Nomex

3. Cross-ply carbon fiber lamina [0/90]

Based on my preliminary research, honeycomb Nomex can be considered as an orthotropic material. 

Also, I know that cross-ply carbon fiber are orthotropic material

Therefore, I was wondering if it would be possible (and perhaps simpler) to consider the sandwich as a single 3D orthotropic material (MAT9OR)

or maybe 2D orthotropic material (MAT8) since the total thickness is very small (around 5 mm).

Furthermore, if I want to run FEA to check bending, is there any properties in the material Data card that I could potentially discard or does the software needs all the properties for such analysis?

Finally, if anyone knows good documentation on this subject, do not hesitate to send some references.

Thank you,

Frédéric Auger