When creating a new solid, the global coordinate system is used by default as the geometric coordinate system of the solid and also as the calculation coordinate system for the results.
To deviate from the default setting, the "Specific Direction..." option is available:
By activating the option, you gain access to the corresponding new tab. The settings within this tab affect the geometric coordinate system of the solid and at the same time also the coordinate system to which the calculation results, such as the principal stresses, are referred:
Here you have the possibility to switch the coordinate system of the solid to a user-defined coordinate system:
If the "Specific Direction..." option is subsequently deactivated, the last selected coordinate system remains in use for the solid. There is also the option to further rotate the reference system of the solid.
The following figure shows the coordinate systems of the solids for solids with different specific direction settings:
The next figures show the coordinate systems of the individual finite elements of the solids:
Finally, we can look at the principal stress results in the z-direction. As can be seen in the figure, these refer to the z-axis of the finite elements:
