Composite Panel Analysis (COSMOS)

[ansansolis]

I am using COSMOSWorks Advanced Professional. I know it supports linear orthotropic materials. I am trying to do a study with aluminum skins versus carbon fiber skins with an aluminum honeycomb core. Is there any way I can analyze my model as 2 skins and a core?
I have modeled the core with the appropriate thickness. I create the inner and outer skins by knit surfacing the core faces and applying a material to the surfaced parts. I select all the appropiate faces for a surface mesh and then apply the thicknesses. I don't know which direction it is extruding to generate the thickness of the mesh.
For the aluminum skin model this seems to work because it'll use the solid material (aluminum) for the whole model. When I change the material properties to carbon fiber for the surfaced parts, the properties follow the properties of the solid; I think this is because surfaces are treated as zero-thickness. I've also been told that the only way to analyze this problem is to model the composite as a single solid with the collective properties of the finished panel. Any suggestions??
I also have trouble locating material properties for carbon fiber. I'm looking for orthotropic values (x-, y-, and z-directions).
Thanks for your time. Any directions (pun intended) will be greatly appreciated.

 

[engAlright]

Without sounding too negative, I wouldn't even bother trying to solve this problem with CosmosWorks. The mode of failure for a laminate is not yield (to fracture), it's usually de-lamination. De-lamintion will usually occur before yield, and it is a very difficult effect to predict. It would include not only the strength of the layers, but the strength of the bond between the layers, "grain" direction of the materials, "crush" direction of the core etc. To my knowledge, COSMOSWorks does not include any kind of functionality to simulate this effect.

Back in "the day" I tried to do this type of thing using SDRC Ideas and found that the amount of work you went through to create an accurate study to produce accurate results was hardly worth it - it was easier just to make a test piece and go down to the lab and break it.

That's just my 2 cents - maybe some aerospace folks would have some more in-depth insights...