Optimizing Spar and Rib location as Assuming wing box as stiffened panel

[ksi8518]

I'm trying to optimize number and location of spars and ribs.  It is painful to create numerous model and figure out which model is the best.

So I'm thinking, if I assume whole wing box as stiffened panel, let's say grid stiffened, then hypersizer could locate best rib position for me.  Is it gonna work?  I believe stiffened panel must be using plate equation, and 3-D wing box may not be suitable for this problem. If so, is there any simple way to optimizing inner structure location like spars and ribs?

Thanks.

[James]

I don't think using a grid stiffened concept to optimize the 90 degree rib spacing is a good approach.

I think a better approach is to use the Non-FEA project capability to optimize the stiffened panel concept with varying X-spans. Using this approach you can develop weight trends vs. rib spacing.

A similar approach was used for the Ares V Interstage structure.
http://hypersizer.com/industry/projects/NASA-Ares-V-Interstage.php

For a more detailed explanation, see Section 2.1:
http://hypersizer.com/download.php?type=pdf&file=AIAA2010_Ares_V_Interstage_Composite_Panel_Concept_and_Ringframe_Spacing_Trade_Studies.pdf

-James