COMSOL Multiphysics™

elshape
TABLE 1-20: BASIC MESH ELEMENT TYPE IDENTIFIERS FOR ELEMENT TYPES GENERATED IN MESHES
NAME
ls(3)
b(3)
lb(3)
prism
lprism
DESCRIPTION
3D simplex (tetrahedron), linear shape generated away from
boundaries and edges in 3D
3D brick (hexahedron, hex), higher-order shape generated in
a layer closest to boundary surfaces and free edges
3D brick (hexahedron, hex), trilinear shape generated away
from boundaries and edges in 3D
3D prism (pentahedron, wedge), higher-order shape
generated in a layer closest to boundary surfaces and free
edges
3D prism (pentahedron, wedge), bilinear shape generated
away from boundaries and edges in 3D
The shapename identifier selects a shape function for the base mesh type, and the
format of the shapeparams parameter in turn depends on the particular shape
function. Typically, the shape function expects a struct with fields specifying
dependent variable name and order.
If there are multiple mesh cases present in the model, the shelem field is a struct
with fields default, case and mind. The default field has the same syntax as
described above for the shelem field itself. Multiple alternate cases which use the
same shape functions can be grouped together using the mind field. This field is a
cell array containing groups of mesh case numbers, each group, caselist, given as
a cell array. For each element mesh case group, elmcase, an alternate shape list is
given in the case field.
Cautionary
Multiple shape functions can be specified by the same elshape element simply by
repeating a basic mesh type name with different shape function and/or parameters
in the shelem field. This means that there also has to be some conflict resolution.
When multiple shape functions specify the same dependent variable name, the one
with the highest interpolation order for the basic field prevails.
The field variables defined on a given domain are the union of the variables defined
in the default case by shape functions on all basic mesh element types on that
domain. This means that variables can at times be missing on certain mesh element
types or for certain mesh cases.
Examples
Add a dependent variable lm on the boundary that can be used as a Lagrange
multiplier in a weak constraint.
clear fem;
107