I would like to determine a principal stress direction though the thickness of a pressure vessel.
The pressure vessel is modelled with a 1°order brick element and constrained with axisymmetric constraints.
After the analysis I obtain this plot:
Autodesk Nastran Von Mises results
I need to extrapolate the principal stress direction in nodes along the thickness in the major stressed area.
I use arrow contour style but principal stress are oriented along the Global coordinate system (the reference coordinate system in the various figures).
Principal stress along global coordinate system
I then insered a local coordinate system, oriented with 1 of the axis though the thickness.
Local coordinate System
And then I selected the new coordinate system:
New Coordinate system
THE PROBLEM IS:
After the definition of new coordinate system, the vector are aligned to these vector, BUT THE VALUE ARE THE SAME.
No stress difference
I neew to extrapolate (plotting and list in data table, the 6 stress tensor component, to using them in other software.
Can anyone help me?
I attach modfem ad .FNO results.