Analysis of Curved Panel

[TDI]

I want to find the stresses in a panel which is part of a wing leading edge. The panel is curved in one direction (fwd - aft) and is subject to a uniform pressure load and tension in plane loads from wing bending. I can find a method for a flat plate for these loading conditions but not for a curved plate. Does anyone know of a suitable method?

 

[rb1957]

why not consider your curved panel as 1/2 of a tube, loaded in bending and internal pressure ... that sounds pretty straight-forward

 

[40818]

A curved panel with inplane loading and pressure should be reasonably easy to find in the usual book list. Could you explain a bit more about the actual panel your interested in, is it a "D" shape or just a portion of it with limited curvature?

 

[TDI]

40818
It is just a portion of a leading edge with limited curvature. I've had a look in Bruhn & Nui but they seem to only give compression + pressure cases and look at panel buckling. In my case I have tension plus pressure.
ESDU seems to have a datasheet but my a/b ratio is outside the limits of the datasheet, hence I'm looking for an alternative method.

 

[40818]

As a simple exercise, i would start with superposition of the stresses for the individual cases. I will have a look around my stuff and see if i can find an example of your problem.

 

[rb1957]

yeah, bruhn et al would be interested in buckling panels, but this probably won't happen in a tension structure.

the internal stresses due to pressure are easy, right.

so is the problem how to stress the L/E in bending ?

'cause superimposing the two internal stresses is also easy (stress_xx and stress_yy, maybe a little shear_xy, would suggest a von mises failure criteria).

 

[40818]

Mr Mises and his Von never did me any harm with wing structures.
But back to the post, is your structure plain skin, or does it contain stiffening members?
If your structure can be considered as a membrane (i.e it is so thin that it may be considered to carry no bending), then its an easy job of the membrane tension added to the direct tension.
If there is only a limited curvature then you could just consider it as a flat plate, the effect of the curvature will stiffen the panel.
Is tension loading due to wing bending really the design critical case?? If i extrapolate, if its in tension due to wing bending and pressure then its a flight case, so the panel must be on the underside of the wing. The pressure and flight WB cases will probably be less than landing (ground) cases which will if im correct give a high compression load onto the panel and give rise to potential buckling.