Bending and Torsional stiffness of Closed Profile hat/Omega stringer

[HawkOkeoJr]

Hallo Engineers,
I am a little bit confused here and i need some guidance.
Can any of you educate me on how to calculate the Bending and Torsional stiffness of a Hat/Omega stringer attached on a plate to form a fuselage panel?..You can also recommend to me a book where it is clearly described so that i can get in-depth with the topic.
The material is Aluminium by the way.
Thank you guys in advance, i will really appreciate the help.

 

[GregLocock]

I'd be amazed if Bruhn doesn't discuss it, seeing as you are in aero. Anyway, bending is just the usual first year stuff, sigma dA*y^2, and parallel axis theorem.

Torsional stiffness of thin walled closed tubes of arbitrary shape with varying wall thickness is not as simple as using an equation, if you want a result that is meaningful. In your case identifying the axis of rotation is tricky. Once you find it then just add the torque contributions of the shear stress. Again Bruhn is probably a good place to start. Or FEA.


Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[GregLocock]

Case & Chilver give an approximate method for thin walled tubes. BUT it is meant for tuby things, not stringers on skins.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?