Abaqus Analysis User's Manual  


27.3.2 Infinite element library

Products: Abaqus/Standard  Abaqus/Explicit  Abaqus/CAE  

References

Element types

Plane strain solid continuum infinite elements

CINPE44-node linear, one-way infinite
CINPE5R(S)    5-node quadratic, one-way infinite

Active degrees of freedom

1, 2

Additional solution variables

None.

Plane stress solid continuum infinite elements

CINPS44-node linear, one-way infinite
CINPS5R(S)    5-node quadratic, one-way infinite

Active degrees of freedom

1, 2

Additional solution variables

None.

3-D solid continuum infinite elements

CIN3D88-node linear, one-way infinite
CIN3D12R(S)    12-node quadratic, one-way infinite
CIN3D18R(S)    18-node quadratic, one-way infinite

Active degrees of freedom

1, 2, 3

Additional solution variables

None.

Axisymmetric solid continuum infinite elements

CINAX44-node linear, one-way infinite
CINAX5R(S)    5-node quadratic, one-way infinite

Active degrees of freedom

1, 2

Additional solution variables

None.

2-D acoustic infinite elements

ACIN2D22-node linear, acoustic infinite
ACIN2D3(S)    3-node quadratic, acoustic infinite

Active degree of freedom

8

3-D acoustic infinite elements

ACIN3D33-node linear, acoustic infinite triangular element
ACIN3D44-node linear, acoustic infinite quadrilateral element
ACIN3D6(S)    6-node quadratic, acoustic infinite triangular element
ACIN3D8(S)    8-node quadratic, acoustic infinite quadrilateral element

Active degree of freedom

8

Axisymmetric acoustic infinite elements

ACINAX22-node linear, acoustic infinite
ACINAX3(S)    3-node quadratic, acoustic infinite

Active degree of freedom

8

Nodal coordinates required

Plane stress and plane strain solid continuum elements: X, Y

2-D acoustic elements: X, Y

3-D solid continuum and acoustic elements: X, Y, Z

Axisymmetric solid continuum and acoustic elements: r, z

Normal directions are not specified at nodes used in acoustic infinite elements; they will be computed automatically. See “Infinite elements,” Section 27.3.1, for details.

Element property definition

For two-dimensional, plane strain, and plane stress elements, you must provide the thickness of the elements; by default, unit thickness is assumed.

For three-dimensional and axisymmetric solid elements, you do not need to specify a thickness.

For acoustic elements, you must specify the reference point in addition to the thickness.

Input File Usage:          
*SOLID SECTION

Abaqus/CAE Usage:   Only acoustic infinite sections are supported in Abaqus/CAE.

Property module: Create Section: select Other as the section Category and Acoustic infinite as the section Type


Element-based loading

None.

Element output

Stress, strain, and other tensor components

No output is available from Abaqus/Explicit for infinite elements. Stress and other tensors (including strain tensors) are available from Abaqus/Standard for infinite elements with displacement degrees of freedom. All tensors have the same components. For example, the stress components are as follows:

S11

direct stress or radial stress for axisymmetric elements.

S22

direct stress or axial stress for axisymmetric elements.

S33

direct stress (not available for plane stress elements) or hoop stress for axisymmetric elements.

S12

shear stress or shear stress for axisymmetric elements.

S13

shear stress (not available for plane stress, plane strain, and axisymmetric elements).

S23

shear stress (not available for plane stress, plane strain, and axisymmetric elements).


Node ordering and face numbering on elements

Plane stress and plane strain solid continuum elements

Axisymmetric solid continuum elements

Three-dimensional solid continuum elements

Two-dimensional and axisymmetric acoustic infinite elements

Three-dimensional acoustic infinite elements

Numbering of integration points for output

Plane stress and plane strain solid continuum elements

Axisymmetric solid continuum elements

Three-dimensional solid continuum elements

This shows the scheme in the layer closest to the 1–2–3–4 face. The integration points in the second layer are numbered consecutively.