For all elements except the special-purpose stress/displacement elements, the third character indicates the space in which the element exists.
Beam elements
2 Two-dimensional
3 Three-dimensional
o Three-dimensional, open section
Continuum elements
1 One-dimensional
2 Two-dimensional
3 Three-dimensional
a Axisymmetric
c Cylindrical
e Plane strain
g Generalized plane strain
n Nonlinear axisymmetric with asymmetric deformation
s Plane stress
Fluid elements
2 Two-dimensional
3 Three-dimensional
a Axisymmetric
l Fluid link
Gasket elements
2 Two-dimensional
3 Three-dimensional
a Axisymmetric
e Plane strain
l Three-dimensional line
s Plane stress
Interface or surface interaction elements
1 One-dimensional
2 Two-dimensional
3 Three-dimensional
a Axisymmetric
b Three-dimensional beams
c Cylindrical gap
g General
p Planar general
s Spherical gap
u Unidirectional gap
Membrane elements
3 Three-dimensional
a Axisymmetric
g Generalized axisymmetric
c Cylindrical
Pipe elements
2 Two-dimensional
3 Three-dimensional
Rigid elements
p Two-dimensional plane stress/plane strain
2 Two-dimensional beam
3 Three-dimensional
a Axisymmetric
Shell elements
3 Three-dimensional (heat transfer or coupled temperature-displacement)
5 Three-dimensional, five degrees of freedom
6 Three-dimensional, six degrees of freedom
a Axisymmetric
c Continuum
e Three-dimensional, enhanced finite strain, full integration
f Three-dimensional, finite strain
n Nonlinear axisymmetric with asymmetric deformation
Truss elements
2 Two-dimensional
3 Three-dimensional