INFIN111


3D Infinite Solid

Valid Products: Pro | Premium | Enterprise | PrepPost | Solver | AS add-on

INFIN111 Element Description

INFIN111 models an open boundary of a 3D unbounded field problem. A single layer of elements is used to represent an exterior sub-domain of semi-infinite extent. The layer models the effect of far-field decay in magnetic, electrostatic, thermal, or electric current conduction analyses. For information about enclosed elements and analysis types, see Table 111.1: INFIN111 Analyses. See INFIN111 in the Mechanical APDL Theory Reference for more details about this element.

Figure 111.1: INFIN111 Geometry

INFIN111 Geometry

INFIN111 Input Data

The geometry, node locations, and the coordinate system for the element are shown in Figure 111.1: INFIN111 Geometry. KEYOPT(1) specifies the degree(s) of freedom to be used. KEYOPT(2) specifies whether a 8-node or 20-node element is used.

Only one layer of INFIN111 elements should be used between the finite element model and the exterior (infinite) surface. The nodes may be input starting at any corner node, but the face opposite of the finite element model (the exterior face) must be flagged as an infinite surface. This is usually done by selecting the nodes at the outer surface and issuing the SF,all,INF command. The other faces have no meaning. For best results, edges connecting the inner and outer surfaces of the infinite element should be radial from the center of the model.

A summary of the element input is given in "INFIN111 Input Summary". A general description of element input is given in Element Input.

INFIN111 Input Summary

Nodes
I, J, K, L, M, N, O, P (if KEYOPT(2) = 0)
I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, A, B (if KEYOPT(2) = 1)
Degrees of Freedom

Set by KEYOPT(1). See Table 111.1: INFIN111 Analyses.

Real Constants

None

Material Properties

See Table 111.2: INFIN111 Material Properties.

Surface Loads
Infinite Surface Flags -- 
face 1 (J-I-L-K), face 2 (I-J-N-M), face 3 (J-K-O-N),
face 4 (K-L-P-O), face 5 (L-I-M-P), face 6 (M-N-O-P)
Body Loads

None

Special Features

None

KEYOPT(1)

Element degree of freedom. See Table 111.1: INFIN111 Analyses.

KEYOPT(2)

Element definition:

0 -- 

8-node brick

1 -- 

20-node brick

KEYOPT(6)

Electric charge reaction sign:

0 -- 

Negative

1 -- 

Positive

Analysis categories are shown in the following table. KEYOPT(1) specifies the element degree of freedom.

Table 111.1: INFIN111 Analyses

Analysis CategoryKEYOPT(1)DOF LabelReaction SolutionEnclosed ElementsAnalysis Type
Magnetic0MAG

Magnetic Flux

(F label = FLUX)

SOLID5

SOLID96

SOLID98

Static

Electrostatic2VOLT

Electric Charge

(F label = CHRG)

SOLID122

SOLID123

Static

Harmonic

Thermal3TEMP

Heat Flow

(F label = HEAT)

SOLID70

SOLID87

SOLID90

Steady-state

Transient

Electric Current Conduction4VOLT

Electric Current

(F label = AMPS)

SOLID231

SOLID232

Steady-state

Harmonic

Transient


INFIN111 material properties are shown in the following table. Nonzero material properties must be defined. Material properties are defined with the MP, MPDATA and EMUNIT commands.

Table 111.2: INFIN111 Material Properties

Analysis CategoryKEYOPT(1)Material Properties
Magnetic0MUZERO
Electrostatic2PERX, PERY, PERZ, LSST, RSVX, RSVY, RSVZ
Thermal3KXX, KYY, KZZ, DENS, C
Electric Current Conduction4RSVX, RSVY, RSVZ, LSST, PERX, PERY, PERZ

INFIN111 Output Data

The solution output associated with the element is in two forms:

The element output directions are parallel to the element coordinate system. A general description of solution output is given in Solution Output. See the Basic Analysis Guide for ways to view results.

The Element Output Definitions table uses the following notation:

A colon (:) in the Name column indicates that the item can be accessed by the Component Name method (ETABLE, ESOL). The O column indicates the availability of the items in the file jobname.out. The R column indicates the availability of the items in the results file.

In either the O or R columns, “Y” indicates that the item is always available, a letter or number refers to a table footnote that describes when the item is conditionally available, and “-” indicates that the item is not available.

Table 111.3: INFIN111 Element Output Definitions

NameDefinitionOR
ELElement NumberYY
NODESNodes - I, J, K, L, M, N, O, P (if KEYOPT(2) = 0); Nodes - I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, A, B (if KEYOPT(2) = 1)YY
MATMaterial numberYY
VOLU:VolumeYY
XC, YC, ZCLocation where results are reportedY4
MUZEROMagnetic permeability of free space11
PERX, PERY, PERZElectric relative permittivity22
KXX, KYY, KZZThermal conductivity33

  1. If KEYOPT(1) = 0

  2. If KEYOPT(1) = 2

  3. If KEYOPT(1) = 3

  4. Available only at centroid as a *GET item.

Table 111.4: INFIN111 Item and Sequence Numbers lists output available through the ETABLE command using the Sequence Number method. See The General Postprocessor (POST1) in the Basic Analysis Guide and The Item and Sequence Number Table in this reference for more information. The following notation is used in Table 111.4: INFIN111 Item and Sequence Numbers:

Name

output quantity as defined in the Table 111.3: INFIN111 Element Output Definitions

Item

predetermined Item label for ETABLE command

E

sequence number for single-valued or constant element data

Table 111.4: INFIN111 Item and Sequence Numbers

Output Quantity NameETABLE and ESOL Command Input
ItemE
MUZERONMISC1
PERXNMISC1
PERYNMISC2
PERZNMISC3
KXXNMISC1
KYYNMISC2
KZZNMISC3

INFIN111 Assumptions and Restrictions

INFIN111 Product Restrictions

When used in the product(s) listed below, the stated product-specific restrictions apply to this element in addition to the general assumptions and restrictions given in the previous section.

Ansys Mechanical Pro  —  

  • The MAG, and VOLT degrees of freedom are not active. KEYOPT(1) defaults to 3 (TEMP) instead of 0 and cannot be changed.

Ansys Mechanical Premium  —  

  • The MAG, and VOLT degrees of freedom are not active. KEYOPT(1) defaults to 3 (TEMP) instead of 0 and cannot be changed.