X-Nico

unusual facts about Jacobian matrix and determinant



Barsoum elements

For these locations of the mid nodes, the Jacobian becomes singular at the corner node thus making displacement derivatives infinite and stresses and strains become infinite as well.

Structural stability

As a consequence of the Denjoy theorem, an orientation preserving C2 diffeomorphism ƒ of the circle is structurally stable if and only if its rotation number is rational, ρ(ƒ) = p/q, and the periodic trajectories, which all have period q, are non-degenerate: the Jacobian of ƒq at the periodic points is different from 1, cf Circle map.


see also