uniaxially stiffened sandwich panels

[composites1]

Is hypersizer capable of performing analysis of, for instance, a sandwich panel siffened by a sandwich blade or z?

I have tried this by modeling the panel as a uniaxially z stiffened panel with the following approach...
 I input the facesheet as a laminate which includes core. Then, I defined the z stiffener as a hyperlaminate including longitudinal, and shear plies, as well as core in the web of the z.  I haven't had much luck with getting this to work.  If there is any confusion, I have attached a .ppt of what I'm trying to simulate.

[Phil]

I would expect this approach to work for sizing for laminate strength, local buckling of the members (i.e. of the span between stiffeners, the blade itself, etc), global buckling of the panel, crippling, and crippling/buckling interaction.  The piece of the puzzle that will be missing is any kind of sandwich failure mode such as wrinkling, crimping, dimpling, or any of the core failure modes such as core shear strength.  For purposes of being placed in a laminate, a core material is used for to introduce a gap between plies for bending stiffness, but for the most part is treated as a void.  So it does not contribute to in-plane stiffness and is not included in the failure analysis. 

Therefore, the thing to be aware of when using HyperSizer for this type of panel is that it will not tell you anything about which core material you should use or whether the members will fail in any kind of sandwich failure mode.

When you say you haven't had much luck getting it to work, what are you referring to?  Is the code having a problem?  Or do you not know which options to choose to make the panel type you want?  If that is the case, I can help with that.

[composites1]

Thank you for your reply.  I see the failure mode correlations that you suggested.  One more question... The manual shows a diagram for defining a hat stiffener with a hyperlaminate.  Does a Z section get defined the same way?  L2 = top flange, L3 = shear web, L4 = bottom flange?

[Phil]

Yes,  You are correct. 

For all uniaxial and corrugated panels:

L2 = Top Flange
L3 = Web
L4 = Bottom Flange (or Crown for a hat)

There are a couple of other articles here that are related to the L2, L3, L4 so you might want to do a search on the keyword "L2" in the forum to read those other articles.