How to extract (vector valued) displacement magnitude + questionable highest stress not in contact area

[violetus]

@hunterr

Question 1: How can i automatically evaluate maximum displacements and stresses in general?
This Example in the FEniCS legacy used the dot product and a projection for accomplishing this task. How can it be done using FEniCSx?

See Electromagnetics example FEniCSx and

How to compute the strain & stress matrices?

A projection is simply solving \int_\Omega u \cdot v ~\mathrm{d}x = \int_\Omega f \cdot v ~\mathrm{d} x which is easy to implement in DOLFINx: A more scalable approach than the route taken in DOLFINy is to create a projector class, that caches the mass matrix, so that you do not have to re-assemble (and refactorize in the case of LU) if you use it multiple times). For the quadrature points (in physical space), consider the first bit of: Numerical values from ufl.SpatialCoordinate - #2 by …