I observed some problems while analyzing my structure in HyperView. I still put my thread in the preprocessing forum, as I think the problem arises during preprocessing.

The tube is meshed with 2D -> automesh -> QI optimized.
Mesh type: mixed
second order elements
The surfaces of the lower section (and also top section, which is not displayed) of the tube were trimmed to get a better mesh orientation in the middle section of the tube.
I would expect all Syy vectors to point into the same direction. So they should point from bottom left to top right in the picture. But some (in the trimmed section) are pointing in a perpendicular direction. This direction (in my opinion) should be Sxx and not Syy.
Is there any possibility to change the orientation of the affected elements?
BTW: The shell normals of all elements is pointing into the same direction. But I think this wouldn't affect the orientation of the element x and y axis.
What else could be the problem?