Flexural-torsional instability & lateral instability of J-type stiffener

[ohba]

Can you let me know how to have HS include the torsional/lateral instability of the stiffener for the uni-axial stiffened panel family.
That is a quiet common made of failure for "skinny" tall stiffener.
When I do the analysis / optimization using HS, I see that failure mode in the list under the failure tab (sizing form) but there is no MoS calculated.
How do we force HS to calculate a MoS for that failure mode

Thanks

[Phil]

Currently this failure mode has been made inactive. We are currently working this method to make it better. In the meantime, we are putting some geometric checks into HyperSizer to disallow cross sections that are prone to torsional/lateral instability from being considered. We are programming those dimensional checks now.

If there are existing rules-of-thumb to use that include the L, H, EI, GJ, web thickness, flange thickness, flange width, etc into account, we would be glad to consider them.

[ToddNewkirk]

Phil,

Where can I find a description of the cross-section dimensional checks that were added back in 2009 to minimize lateral instability?

Thanks,
Todd

[Phil]

The flexural-torsional stability failure mode (primarily the Argyris method) is fully functional in the latest versions of HyperSizer  (starting in version 5.9, I believe).

The geometry checks are described in the HyperSizer help system. 

http://hypersizer.com/help/Content/Failure/geometry.php

Let me know if you have more questions.