Hi Mani,

You opened this topic with a statement that you were getting ridiculous mode shapes from an orthotropic material. I was curious to see those shapes, but you took the orthotropic material out when you shared your model so I have not yet seen what you meant by that. Will I get a chance to see that?

You moved on to explicitly modeling the honeycomb cells. You can assign double the thickness to those faces that need it.

You say you plan to use the results of the honeycomb cell model to adjust the values of the orthotropic core material until the results match. You make it sound simple, but what you are saying is actually complicated. 

What loads and boundary conditions you will use on the two models?  What result will you pull from each model? 

There are nine material constants in the orthotropic material model, how will you adjust those nine numbers based on a comparison of the results between the two models?  Will you keep the honeycomb vendor values constant? There is a constraint equation involving the nine constants that must be satisfied, so you are not free to choose values that don't satisfy the constraint. How will you incorporate the constraint equation in your value update method?