Honeycomb panel test

[ghfjdkjlhk]

Hi:

Recentlly we tested a composite panel for uniform pressure load and tablulated the deflection at few location where we were intersted.But when I tried to use hand equations to calculate the stiffness/deflection and I got totally diffefrent results for deflection.Actually deflections are more in hand eqations.

Now am I wondering which deflection to use to calculate stiffness.

If I use from hand results, stiffness (total load from pressure /deflection)is not acceptable because sfiffness is small than required.

Can anyone tell what I am missing?

Thanks in adwanse.

 

[Onda]

Did you take in account the shear deflection? for an honeycomb panel isn't negligible.
Onda

 

[IFRs]

Hexcel published some technical papers dealing with the strength and deflection of composite structures. If you are using such a structure (metallic skins glued to a hex-cell core), they can help.

 

[SWComposites]

What boundary conditions were used for the test panel?
How was the load applied?
What boundary conditions were used in your analysis?
Is it a constant thickness panel, or do the facesheets ramp down into a laminate edgeband?
Have you included transverse shear deflection in your analysis?