Principal stress/strain directions displayed as triads
issueid=594 11-07-2012 09:35 PM
Principal stress/strain directions displayed as triads

Hi Steve,

Sometimes it would be nice to see all three principal directions of stress (or strain) simultaneously, as an orthogonal triad, instead of just looking at the first, second or third principal direction alone.

The length of the arrows (or whichever other glyph is used) in the triad could be proportional to the magnitude of the principal value.

More specifically, as I've seen on some commercial FEM software, we can have two arrows drawn for each principal direction, either pointing away from each other (when the principal value is positive) or toward each other (when negative). This way, in one fell swoop, we can get complete information about the stress or strain tensor at a point.

What do you think?


Issue Details
Issue Number 594
Issue Type Feature
Project PostView
Category Unknown
Status Accepted
Priority 5 - Medium
Suggested Version Unknown
Implemented Version (none)
Votes for this feature 1
Votes against this feature 0
Assigned Users maas
Tags (none)

11-08-2012 12:39 PM
Lead Code Developer
Hi Gerard,

I think this is a great idea. I will look into it.



11-08-2012 12:55 PM


11-14-2012 03:34 AM
If I am not mistaken single principal components can be plotted as vectors using the vector plots. Users could also use this format for this purpose if you allow multiple vector plots to be combined. For instance plot unit principal vectors for the 1, 2, and 3 directions together and colour them towards principal values.

It would also be nice to overlay the material axis directions or fibre direction vectors to see if the reinforcement directions coincide with the principal strain directions.

For a fibre direction vector plot it would also be nice to colour/scale the vectors according to the along fibre stretch magnitude.


11-11-2013 02:58 PM
Hi Steve,

Have you had a chance to look into this implementation?



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