Hoop stresses 1

[GDfern]

Hoop stresses on fuselage
Hoop stresses on fuselage are mainly taken from the skin, there’s also a significant load taken by the frames. I have seen in many analysis that they ignore the contribution from the frame. Assuming that all hoop load is taken by skins that is a very conservative approach. Sometimes this could yield to heavier skins..
Any thoughts?

 

[rb1957]

this is in my experience a very common approach. for my money it is accurate for the mid-frame bay skin, and conservative for the skin at the frame.

another day in paradise, or is paradise one day closer ?

 

[LiftDivergence]

If you are interested, try searching for:

Miller, M., Gruber, M. L., Wilkins, K. E., & Worden, R. E., N95-14485, Titled, “Full-Scale Testing and Analysis of Fuselage Structure,” The Boeing Company, Seattle, WA

There is some discussion about the stress profile and a reduction factor near the reinforcing substructure. In my experience this is only considered in certain cases when trying to develop a crack growth stress for specific DTA scenarios. Of course, it is usually conservative to ignore the substructure.

Keep em' Flying
//Fight Corrosion!

 

[der8110]

yes, very conservative to consider only the skin. A pretty easy way to account for frames is to use Flugge, NACA TN 2612.

 

[rb1957]

calc i've seen using flugge stress aren't That different to hoop stress.

FEM I've made show that mid bay the skin is reacting hoop stress. local to frames stress is smaller.

another day in paradise, or is paradise one day closer ?