Command manual

Change element polynomial order in a selected region of a part or part set.

Change of polynomial order

The following command defines a region in space where linear elements are converted to cubic.

Converting polynomial order of elements inside a cylinder (geometry 123)

Linear vs. cubic elements

Two cantilever beams are subjected to a transverse point load at the unconstrained end. One of the beams is modeled with five LHEX (Linear hexagonal) elements and the other with five CHEX (Cubic hexagonal) elements. From Euler-Bernoulli beam theory, the maximum deflection, $\mathbf\delta_{max}$ is:

$\mathbf\delta_{max} = \displaystyle{ \frac{PL^3}{3EI} } = \displaystyle{ \frac{1.0e4 \cdot 1.0^3}{3 \cdot 200e9 \cdot \frac{0.05 \cdot 0.05^3}{12}} = 32 mm}$

where, $P$ is the applied load, $L$ is the length of the beam, $E$ is the elastic modulus and $I$ is the moment of inertia. The higher order elements are superior to the linear elements for this model setup.