Wing Skin Buckling on FEMAP Model

[mbrowntx1]

I'm working on a T-34 wing model after an in flight failure. At ultimate flight loads the upper wing skin is buckled so I used CShear elements that will not take normal force and used rod elements to model the effective skin. Even using permanent constraits 45&6 and Auto SPC on, the deformed output veiw shows unrealistic out of plane deformation. I'm loading the model with pressure on the skin for the airloads. I have three skin elements between each rib. I have rod elements around every CShear element. How can I get the wing skin to take the shear loads but no normal loads?

 

[KSshopper]

When a skin buckles, it still carries the load it carried at the onset of buckling. Any additional load is transfered to the stringers and "effective" skin.

Another approach may be in order. Change your CShear elements to Plates (Shell64 in ANSYS). Change your Rods to Beams. Then try doing a buckling analysis. A buckling analysis requires a mesh finer than that required for a static run, so you may need to remesh.

Good luck.