30.3.2 Rigid element library

Products: Abaqus/Standard Abaqus/Explicit Abaqus/CAE

References

Overview

This section provides a reference to the rigid elements available in Abaqus/Standard and Abaqus/Explicit.

Element types

2D rigid elements

R2D2 2-node, linear link (for use in plane strain or plane stress)
RAX2 2-node, linear link (for use in axisymmetric planar geometries)
RB2D2^(S) 2-node, rigid beam

Slave degrees of freedom

R2D2 and RAX2: 1, 2

RB2D2: 1, 2, 6

Master degrees of freedom

R2D2, RAX2, and RB2D2: 1, 2, 6 at the rigid body reference node

Additional solution variables

None.

3D rigid elements

R3D3 3-node, triangular facet
R3D4 4-node, bilinear quadrilateral
RB3D2^(S) 2-node, rigid beam

Slave degrees of freedom

R3D3 and R3D4: 1, 2, 3

RB3D2: 1, 2, 3, 4, 5, 6

Master degrees of freedom

1, 2, 3, 4, 5, 6 at the rigid body reference node

Additional solution variables

None.

Nodal coordinates required

R2D2 and RB2D2: X, Y

RAX2: r, z

R3D3, R3D4, and RB3D2: X, Y, Z

Element property definition

For R2D2, RB2D2, and RB3D2 elements you can specify the cross-sectional area of the element. In Abaqus/Standard if no area is given, unit area is assumed; the area is required in Abaqus/Explicit.

For RAX2, R3D3, and R3D4 elements you can specify the thickness of the element. In Abaqus/Standard if no thickness is given, unit thickness is assumed; the thickness is required in Abaqus/Explicit.

The cross-sectional area or element thickness is used for the purpose of defining body forces, which are given in units of force per unit volume, and, in Abaqus/Explicit, determining the total mass.

Input File Usage:

*RIGID BODY

Abaqus/CAE Usage:

Interaction module: Create Constraint: Rigid body: Body (elements)

Element-based loading

Distributed loads

Distributed loads are available for elements with displacement degrees of freedom. They are specified as described in “Distributed loads,” Section 34.4.3.

Available for R2D2 elements only:

Load ID (*DLOAD):  BX^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Body force in global X-direction.

Load ID (*DLOAD):  BY^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Body force in global Y-direction.

Load ID (*DLOAD):  BXNU^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Nonuniform body force in global X-direction with magnitude supplied via user subroutine DLOAD.

Load ID (*DLOAD):  BYNU^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Nonuniform body force in global Y-direction with magnitude supplied via user subroutine DLOAD.

Load ID (*DLOAD):  CENT^(S)

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–4 (ML^–3T^–2)

Description:  Centrifugal load (magnitude is input as , where is the mass density per unit volume and is the angular velocity).

Load ID (*DLOAD):  CORIO^(S)

Abaqus/CAE Load/Interaction:  Coriolis force

Units:  FL^–4T (ML^–3T^–1)

Description:  Coriolis force (magnitude is input as , where is the mass density per unit volume and is the angular velocity). The load stiffness due to Coriolis loading is not accounted for in direct steady-state dynamics analysis.

Load ID (*DLOAD):  P^(E)

Abaqus/CAE Load/Interaction:  Pressure

Units:  FL^–2

Description:  Pressure on the element surface. The pressure is positive in the direction of the positive element normal.

Load ID (*DLOAD):  PNU^(E)

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–2

Description:  Nonuniform pressure on the element surface with magnitude supplied via user subroutine VDLOAD. The pressure is positive in the direction of the positive element normal.

Available for RAX2 elements only:

Load ID (*DLOAD):  BR^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Body force per unit volume in the radial direction.

Load ID (*DLOAD):  BZ^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Body force per unit volume in the axial direction.

Load ID (*DLOAD):  BRNU^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Nonuniform body force per unit volume in the radial direction, with the magnitude supplied via user subroutine DLOAD.

Load ID (*DLOAD):  BZNU^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Nonuniform body force per unit volume in the z-direction, with the magnitude supplied via user subroutine DLOAD.

Load ID (*DLOAD):  CENT^(S)

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–4 (ML^{– 3}T^–2)

Description:  Centrifugal load (magnitude given as , where is the mass density and is the angular speed). Since only axisymmetric deformation is allowed, the spin axis must be the z-axis.

Load ID (*DLOAD):  HP^(S)

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–2

Description:  Hydrostatic pressure on the element surface and linear in global Z. The pressure is positive in the direction of the positive element normal.

Load ID (*DLOAD):  P

Abaqus/CAE Load/Interaction:  Pressure

Units:  FL^–2

Description:  Pressure on the element surface. The pressure is positive in the direction of the positive element normal.

Load ID (*DLOAD):  PNU

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–2

Description:  Nonuniform pressure on the element surface with the magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit. The pressure is positive in the direction of the positive element normal.

Load ID (*DLOAD):  TRSHR

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  Shear traction on the element surface.

Load ID (*DLOAD):  TRSHRNU^(S)

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–2

Description:  Nonuniform shear traction on the element surface with magnitude and direction supplied via user subroutine UTRACLOAD.

Load ID (*DLOAD):  TRVEC

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  General traction on the element surface.

Load ID (*DLOAD):  TRVECNU^(S)

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–2

Description:  Nonuniform general traction on the element surface with magnitude and direction supplied via user subroutine UTRACLOAD.

Available for R3D3 and R3D4 elements only:

Load ID (*DLOAD):  BX^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Body force in the global X-direction.

Load ID (*DLOAD):  BY^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Body force in the global Y-direction.

Load ID (*DLOAD):  BZ^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Body force in the global Z-direction.

Load ID (*DLOAD):  BXNU^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Nonuniform body force in the global X-direction with magnitude supplied via user subroutine DLOAD.

Load ID (*DLOAD):  BYNU^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Nonuniform body force in the global Y-direction with magnitude supplied via user subroutine DLOAD.

Load ID (*DLOAD):  BZNU^(S)

Abaqus/CAE Load/Interaction:  Body force

Units:  FL^–3

Description:  Nonuniform body force in the global Z-direction with magnitude supplied via user subroutine DLOAD.

Load ID (*DLOAD):  PNU

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–2

Description:  Nonuniform pressure on the element surface with magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit. The pressure is positive in the direction of the positive element normal.

Load ID (*DLOAD):  TRSHR

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  Shear traction on the element surface.

Load ID (*DLOAD):  TRVEC

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  General traction on the element surface.

Abaqus/Aqua loads

Abaqus/Aqua loads are specified as described in “Abaqus/Aqua analysis,” Section 6.11.1.

Available for R3D3 and R3D4 elements only:

Load ID (*CLOAD/ *DLOAD):  PB

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–2

Description:  Buoyancy force.

Available for RB2D2 and RB3D2 elements only:

Load ID (*CLOAD/ *DLOAD):  FDD

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–1

Description:  Transverse fluid drag force.

Load ID (*CLOAD/ *DLOAD):  FD1

Abaqus/CAE Load/Interaction:  Not supported

Units:  F

Description:  Fluid drag force on the first end of the rigid link (node 1).

Load ID (*CLOAD/ *DLOAD):  FD2

Abaqus/CAE Load/Interaction:  Not supported

Units:  F

Description:  Fluid drag force on the second end of the rigid link (node 2).

Load ID (*CLOAD/ *DLOAD):  FDT

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–1

Description:  Tangential fluid drag load.

Load ID (*CLOAD/ *DLOAD):  FI

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–1

Description:  Transverse fluid inertia load.

Load ID (*CLOAD/ *DLOAD):  FI1

Abaqus/CAE Load/Interaction:  Not supported

Units:  F

Description:  Fluid inertia load on the first end of the rigid link (node 1).

Load ID (*CLOAD/ *DLOAD):  FI2

Abaqus/CAE Load/Interaction:  Not supported

Units:  F

Description:  Fluid inertia load on the second end of the rigid link (node 2).

Load ID (*CLOAD/ *DLOAD):  PB

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–1

Description:  Buoyancy force (with closed-end condition).

Load ID (*CLOAD/ *DLOAD):  WDD

Abaqus/CAE Load/Interaction:  Not supported

Units:  FL^–1

Description:  Transverse wind drag force.

Load ID (*CLOAD/ *DLOAD):  WD1

Abaqus/CAE Load/Interaction:  Not supported

Units:  F

Description:  Wind drag force on the first end of the rigid link (node 1).

Load ID (*CLOAD/ *DLOAD):  WD2

Abaqus/CAE Load/Interaction:  Not supported

Units:  F

Description:  Wind drag force on the second end of the rigid link (node 2).

Surface-based loading

Distributed loads

Surface-based distributed loads are available for elements with displacement degrees of freedom. They are specified as described in “Distributed loads,” Section 34.4.3.

Available for RAX2, R3D3, and R3D4 elements only:

Load ID (*DSLOAD):  HP^(S)

Abaqus/CAE Load/Interaction:  Pressure

Units:  FL^–2

Description:  Hydrostatic pressure on the element surface and linear in global Z. The pressure is positive in the direction opposite to the surface normal.

Load ID (*DSLOAD):  P

Abaqus/CAE Load/Interaction:  Pressure

Units:  FL^–2

Description:  Pressure on the element surface. The pressure is positive in the direction opposite to the surface normal.

Load ID (*DSLOAD):  PNU

Abaqus/CAE Load/Interaction:  Pressure

Units:  FL^–2

Description:  Nonuniform pressure on the element surface with the magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit. The pressure is positive in the direction opposite to the surface normal.

Load ID (*DSLOAD):  TRSHR

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  Shear traction on the element surface.

Load ID (*DSLOAD):  TRSHRNU^(S)

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  Nonuniform shear traction on the element surface with magnitude and direction supplied via user subroutine UTRACLOAD.

Load ID (*DSLOAD):  TRVEC

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  General traction on the element surface.

Load ID (*DSLOAD):  TRVECNU^(S)

Abaqus/CAE Load/Interaction:  Surface traction

Units:  FL^–2

Description:  Nonuniform general traction on the element surface with magnitude and direction supplied via user subroutine UTRACLOAD.

Element output

None.

R2D2	2-node, linear link (for use in plane strain or plane stress)

RAX2	2-node, linear link (for use in axisymmetric planar geometries)