GeoMech Vtk import: handle tensor vectors (stress/strain)

[kriben]

E.g. strain[0] first element (and then every third) is E11

[magnesj]

Element nodal result mapping

ResInsight imports stress and strain values on element nodal level. These values are available in VTK files as element results. The following table defines the relationship. The table was established in discussion with @hnil

SA : Stress in Abaqus output format
EA : Stress in Abaqus output format

Component	VTK result name	Result index
SA.S11	stress[0]	0
SA.S22	stress[0]	1
SA.S33	stress[0]	2
SA.S12	stress[1]	0
SA.S13	stress[1]	1
SA.S33	stress[1]	2

Component	VTK result name	Result index
EA.S11	strain[0]	0
EA.S22	strain[0]	1
EA.S33	strain[0]	2
EA.S12	strain[1]	0
EA.S13	strain[1]	1
EA.S33	strain[1]	2

https://resinsight.org/calculated-data/derivedresultsgeomech/index.html

[magnesj]

Initiali prototyping revealed that the file interface for geomechanical data needs more refactoring to be able to import stress/strain from VTK. This is related to naming and the implicit dependency on property names from Abaqus.

Improvements and fixes for displacement was done in #13867

[magnesj]

Stress and strain tensor components from VTK files are now exposed as a folder with sub-items in the UI:

• S_VTK with components S11, S22, S33, S12, S13, S23
• E_VTK with components E11, E22, E33, E12, E13, E23

NB! Note that these values are available on element level. When reading data from Abaqus, these values are exposed on element nodes.