Accurate modeling of honeycomb core

Julian_R

Hello guys,

I try to accurately model the honeycomb core C1-3,2-29. I would like to see the different behavior between the use of solid and 2D elements for the core. 

The problem is that I don't know how to put in the material parameter.

Can someone tell me which constant of the material sheet given by the supplier belongs to which unit in Hypermesh? There is no youngs modulus etc.

I need it for a Mat1 and Mat8 card.

 

Thank you very much!

 

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Robert Lawson

Assuming you're analyzing in Optistruct...   For 2D PCOMP analysis, you would want to use a MAT8 card.  For 3D solid core, you want a MAT9OR card.  HC manufacturers are only giving you the two pertinent shear modulus values.  

 

Assuming X and Y are in-plane, and Z is out-of-plane:

For MAT8, the hear modulus values above are G1z and G2z.

For MAT9OR, the shear modulus values above are G23 and G31.  

 

For MAT9OR, E3 is something significant.  I would start with the modulus of aluminum (assuming aluminum core), and knock it down by the void fraction of the core.

 

The other values are typically small, but probably can't be ignored.  You can easily come up with combinations that don't satisfy the irritable constitutive relationships.