Rigid Element Library

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

This page discusses:

See Also
Rigid Elements
In Other Guides
*RIGID BODY

Products Abaqus/Standard Abaqus/Explicit Abaqus/CAE

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

Secondary Degrees of Freedom

R2D2 and RAX2: 1, 2

RB2D2: 1, 2, 6

Main 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

Secondary Degrees of Freedom

R3D3 and R3D4: 1, 2, 3

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

Main 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/Explicit. The cross-sectional area cannot be specified in Abaqus/Standard.

For RAX2, R3D3, and R3D4 elements you can specify the thickness of the element in Abaqus/Explicit. The thickness of the element cannot be specified in Abaqus/Standard.

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 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.

*dload

Available for R2D2 elements only:

  1. Load ID (*DLOAD): BX (S)
  2. Body force
  3. FL−3

  4. Body force in global X-direction.

  1. Load ID (*DLOAD): BY (S)
  2. Body force
  3. FL−3

  4. Body force in global Y-direction.

  1. Load ID (*DLOAD): BXNU (S)
  2. Body force
  3. FL−3

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

  1. Load ID (*DLOAD): BYNU (S)
  2. Body force
  3. FL−3

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

  1. Load ID (*DLOAD): CENT (S)
  2. Not supported
  3. FL−4 (ML−3T−2)

  4. Centrifugal load (magnitude is input as ρ ⁢ ω 2 , where ρ is the mass density per unit volume and ω is the angular velocity).

  1. Load ID (*DLOAD): CORIO (S)
  2. Coriolis force
  3. FL−4T (ML−3T−1)

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

  1. Load ID (*DLOAD): P (E)
  2. Pressure
  3. FL−2

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

  1. Load ID (*DLOAD): PNU (E)
  2. Not supported
  3. FL−2

  4. 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.

*dload

Available for RAX2 elements only:

  1. Load ID (*DLOAD): BR (S)
  2. Body force
  3. FL−3

  4. Body force per unit volume in the radial direction.

  1. Load ID (*DLOAD): BZ (S)
  2. Body force
  3. FL−3

  4. Body force per unit volume in the axial direction.

  1. Load ID (*DLOAD): BRNU (S)
  2. Body force
  3. FL−3

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

  1. Load ID (*DLOAD): BZNU (S)
  2. Body force
  3. FL−3

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

  1. Load ID (*DLOAD): CENT (S)
  2. Not supported
  3. FL−4 (ML− 3T−2)

  4. Centrifugal load (magnitude given as ρ ω ​ 2 , where ρ is the mass density and ω is the angular speed). Since only axisymmetric deformation is allowed, the spin axis must be the z-axis.

  1. Load ID (*DLOAD): HP (S)
  2. Not supported
  3. FL−2

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

  1. Load ID (*DLOAD): P
  2. Pressure
  3. FL−2

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

  1. Load ID (*DLOAD): PNU
  2. Not supported
  3. FL−2

  4. 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.

  1. Load ID (*DLOAD): TRSHR
  2. Surface traction
  3. FL−2

  4. Shear traction on the element surface.

  1. Load ID (*DLOAD): TRSHRNU (S)
  2. Not supported
  3. FL−2

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

  1. Load ID (*DLOAD): TRVEC
  2. Surface traction
  3. FL−2

  4. General traction on the element surface.

  1. Load ID (*DLOAD): TRVECNU (S)
  2. Not supported
  3. FL−2

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

*dload

Available for R3D3 and R3D4 elements only:

  1. Load ID (*DLOAD): BX (S)
  2. Body force
  3. FL−3

  4. Body force in the global X-direction.

  1. Load ID (*DLOAD): BY (S)
  2. Body force
  3. FL−3

  4. Body force in the global Y-direction.

  1. Load ID (*DLOAD): BZ (S)
  2. Body force
  3. FL−3

  4. Body force in the global Z-direction.

  1. Load ID (*DLOAD): BXNU (S)
  2. Body force
  3. FL−3

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

  1. Load ID (*DLOAD): BYNU (S)
  2. Body force
  3. FL−3

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

  1. Load ID (*DLOAD): BZNU (S)
  2. Body force
  3. FL−3

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

  1. Load ID (*DLOAD): CENT (S)
  2. Not supported
  3. FL−4 (ML−3T−2)

  4. Centrifugal load (magnitude is input as ρ ⁢ ω 2 , where ρ is the mass density per unit volume and ω is the angular velocity).

  1. Load ID (*DLOAD): CORIO (S)
  2. Coriolis force
  3. FL−4T (ML−3T−1)

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

  1. Load ID (*DLOAD): HP (S)
  2. Not supported
  3. FL−2

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

  1. Load ID (*DLOAD): P
  2. Pressure
  3. FL−2

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

  1. Load ID (*DLOAD): PNU
  2. Not supported
  3. FL−2

  4. 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.

  1. Load ID (*DLOAD): TRSHR
  2. Surface traction
  3. FL−2

  4. Shear traction on the element surface.

  1. Load ID (*DLOAD): TRSHRNU (S)
  2. Not supported
  3. FL−2

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

  1. Load ID (*DLOAD): TRVEC
  2. Surface traction
  3. FL−2

  4. General traction on the element surface.

  1. Load ID (*DLOAD): TRVECNU (S)
  2. Not supported
  3. FL−2

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

Abaqus/Aqua Loads

Abaqus/Aqua loads are specified as described in Abaqus/Aqua Analysis.

*cload/ *dload

Available for R3D3 and R3D4 elements only:

  1. Load ID (*CLOAD/ *DLOAD): PB
  2. Not supported
  3. FL−2

  4. Buoyancy force.

*cload/ *dload

Available for RB2D2 and RB3D2 elements only:

  1. Load ID (*CLOAD/ *DLOAD): FDD
  2. Not supported
  3. FL−1

  4. Transverse fluid drag force.

  1. Load ID (*CLOAD/ *DLOAD): FD1
  2. Not supported
  3. F

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

  1. Load ID (*CLOAD/ *DLOAD): FD2
  2. Not supported
  3. F

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

  1. Load ID (*CLOAD/ *DLOAD): FDT
  2. Not supported
  3. FL−1

  4. Tangential fluid drag load.

  1. Load ID (*CLOAD/ *DLOAD): FI
  2. Not supported
  3. FL−1

  4. Transverse fluid inertia load.

  1. Load ID (*CLOAD/ *DLOAD): FI1
  2. Not supported
  3. F

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

  1. Load ID (*CLOAD/ *DLOAD): FI2
  2. Not supported
  3. F

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

  1. Load ID (*CLOAD/ *DLOAD): PB
  2. Not supported
  3. FL−1

  4. Buoyancy force (with closed-end condition).

  1. Load ID (*CLOAD/ *DLOAD): WDD
  2. Not supported
  3. FL−1

  4. Transverse wind drag force.

  1. Load ID (*CLOAD/ *DLOAD): WD1
  2. Not supported
  3. F

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

  1. Load ID (*CLOAD/ *DLOAD): WD2
  2. Not supported
  3. F

  4. 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.

*dsload

Available for RAX2, R3D3, and R3D4 elements only:

  1. Load ID (*DSLOAD): HP (S)
  2. Pressure
  3. FL−2

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

  1. Load ID (*DSLOAD): P
  2. Pressure
  3. FL−2

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

  1. Load ID (*DSLOAD): PNU
  2. Pressure
  3. FL−2

  4. 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.

  1. Load ID (*DSLOAD): TRSHR
  2. Surface traction
  3. FL−2

  4. Shear traction on the element surface.

  1. Load ID (*DSLOAD): TRSHRNU (S)
  2. Surface traction
  3. FL−2

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

  1. Load ID (*DSLOAD): TRVEC
  2. Surface traction
  3. FL−2

  4. General traction on the element surface.

  1. Load ID (*DSLOAD): TRVECNU (S)
  2. Surface traction
  3. FL−2

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

Element Output

None.

Node Ordering on Elements