Post buckling capability of stiffened panel

[ohba]

How dow I allow HS to account for the post buckling behaviour of stiffened panel ?
I know that HS is allow to have negative MS not accounted for in the sizing process (typically we could have buckling of the skin panel at 60 % of the applied load) via the failure tab.

But how do we have HS accounting for the load re-distribution to the stiffeners once the skin are buckled (i.e : in classical analysis, this is done with the effective skin width approach) ? The stiffener can become critical in Euler failure type following since they pick up more load (their initial load + extra additional load from the buckled skin)

[Rocketman007]

In the near future (Second half of 2009), Hypersizer will have a post buckling capability. The user will have the capability to define the allowable buckling ratio.  HyperSizer will redistribute the load from the buckled skin panel to the stiffener. Crippling and Euler Buckling analysis is conducted with the redistributed stiffener load.

Post buckling analysis of metallic structures is the norm. Caution is required if composite panels are allowed to buckle at loads lower than ultimate load. Unpredictable out of plane loads require development and certification stiffened panel sub component tests to validate the analysis.

[HyperSizer Moderator]

Question Submitted via Email:

Does HyperSizer have a complete diagonal tension post buckle analysis?

[Ryan]

An extension of the NACA incomplete diagonal tension method has been implemented for flat panels starting in HyperSizer 6.0.

The latest verification document for the HyperSizer postbuckling methods (compression and shear) is available on the analysis page. Customer login is required.

http://www.hypersizer.com/analysis/CustomerLoginPage.html

Local Postbuckling, Compression & Shear - Verification & Validation