1. Discretization

1.1. Degrees of freedom

Modeling

Degrees of Freedom (at each vertex node)

GRILLE_EXCENTRE	\(\mathit{DX}\): next move \(X\)
	\(\mathit{DY}\): next move \(Y\)
	\(\mathit{DZ}\): next move \(Z\)
	\(\mathit{DRX}\): rotation around \(X\)
	\(\mathit{DRY}\): rotation around \(Y\)
	\(\mathit{DRZ}\): rotation around \(Z\)

GRILLE_MEMBRANE and MEMBRANE	\(\mathit{DX}\): next move \(X\)
	\(\mathit{DY}\): next move \(Y\)
	\(\mathit{DZ}\): next move \(Z\)

1.2. Support mesh for stiffness matrices

The support meshes for finite elements, in displacement formulation, are triangles.

Modeling

Mesh

Finished element

GRILLE_EXCENTRE	TRIA3	MEGCTR3
	QUAD4	MEGCQU4
GRILLE_MEMBRANE	TRIA3	MEGMTR3
	QUAD4	MEGMQU4
	TRIA6	MEGMTR6
	QUAD8	MEGMQU8
MEMBRANE	TRIA3	MEMBTR3
	QUAD4	MEMBQU4
	TRIA6	MEMBTR6
	QUAD8	MEMBQU8
	TRIA7	MEMBTR7
	QUAD9	MEMBQU9

1.3. Cargo support mesh

All the loads applicable to the facets of the grid and membrane elements are treated by direct discretization on the support mesh of the element in displacement formulation.

No load support mesh is therefore necessary for the faces of the grid and membrane elements.