General Surface Element Library

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

This page discusses:

Element Types

SFM3D3

3-node triangle

SFM3D4(S)

4-node quadrilateral

SFM3D4R

4-node quadrilateral, reduced integration

SFM3D6(S)

6-node triangle

SFM3D8(S)

8-node quadrilateral

SFM3D8R(S)

8-node quadrilateral, reduced integration

Active Degrees of Freedom

1, 2, 3

Additional Solution Variables

None.

Nodal Coordinates Required

X, Y, Z

Element Property Definition

Element-Based Loading

Distributed Loads

Distributed loads are specified as described in Distributed Loads. Gravity, centrifugal, rotary acceleration, and Coriolis force loads apply only if the surface elements have rebar defined or if the elements have a defined density.

*dload
  1. Load ID (*DLOAD): BX
  2. FL−2
  3. Body force in the global X-direction.

  1. Load ID (*DLOAD): BY
  2. FL−2
  3. Body force in the global Y-direction.

  1. Load ID (*DLOAD): BZ
  2. FL−2
  3. Body force in the global Z-direction.

  1. Load ID (*DLOAD): BXNU
  2. FL−2
  3. Nonuniform body force in the global X-direction with magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit.

  1. Load ID (*DLOAD): BYNU
  2. FL−2
  3. Nonuniform body force in the global Y-direction with magnitude supplied via user subroutine DLOAD in Abaqus/Standard  and VDLOAD in Abaqus/Explicit.

  1. Load ID (*DLOAD): BZNU
  2. FL−2
  3. Nonuniform body force in the global Z-direction with magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit.

  1. Load ID (*DLOAD): CENT (S)
  2. FL−3 (ML−2T−2)
  3. Centrifugal load (magnitude is input as ρω2, where ρ is the mass density per unit area, ω is the angular speed).

  1. Load ID (*DLOAD): CENTRIF (S)
  2. T−2
  3. Centrifugal load (magnitude is input as ω2, where ω is the angular speed).

  1. Load ID (*DLOAD): CORIO (S)
  2. FL−3T (ML−2T−1)
  3. Coriolis force (magnitude is input as ρω, where ρ is the mass density per unit area, ω is the angular speed). The load stiffness due to Coriolis loading is not accounted for in direct steady-state dynamics analysis.

  1. Load ID (*DLOAD): GRAV
  2. LT−2
  3. Gravity loading in a specified direction (magnitude is input as acceleration).

  1. Load ID (*DLOAD): HP (S)
  2. FL−2
  3. Hydrostatic pressure applied to the element reference surface and linear in global Z. The pressure is positive in the direction of the positive element normal.

  1. Load ID (*DLOAD): P
  2. FL−2
  3. Pressure applied to the element reference surface. The pressure is positive in the direction of the positive element normal.

  1. Load ID (*DLOAD): PNU
  2. FL−2
  3. Nonuniform pressure applied to the element reference 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): ROTA (S)
  2. T−2
  3. Rotary acceleration load (magnitude is input as α, where α is the rotary acceleration).

  1. Load ID (*DLOAD): SBF (E)
  2. FL−5T2
  3. Stagnation body force in global X-, Y-, and Z-directions.

  1. Load ID (*DLOAD): SP (E)
  2. FL−4T2
  3. Stagnation pressure applied to the element reference surface.

  1. Load ID (*DLOAD): TRSHR
  2. FL−2
  3. Shear traction on the element reference surface.

  1. Load ID (*DLOAD): TRSHRNU (S)
  2. FL−2
  3. Nonuniform shear traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD.

  1. Load ID (*DLOAD): TRVEC
  2. FL−2
  3. General traction on the element reference surface.

  1. Load ID (*DLOAD): TRVECNU (S)
  2. FL−2
  3. Nonuniform general traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD.

  1. Load ID (*DLOAD): VBF (E)
  2. FL−4T
  3. Viscous body force in global X-, Y-, and Z-directions.

  1. Load ID (*DLOAD): VP (E)
  2. FL−3T
  3. Viscous surface pressure applied to the element reference surface. The pressure is proportional to the velocity normal to the element face and opposing the motion.

Foundations

Foundations are available only in Abaqus/Standard and are specified as described in Element Foundations.

*foundation
  1. Load ID (*FOUNDATION): F
  2. FL−3
  3. Elastic foundation.

Surface-Based Loading

Distributed Loads

Surface-based distributed loads are specified as described in Distributed Loads.

*dsload
  1. Load ID (*DSLOAD): HP (S)
  2. FL−2
  3. Hydrostatic pressure on the element reference surface and linear in global Z. The pressure is positive in the direction opposite to the surface normal.

  1. Load ID (*DSLOAD): P
  2. FL−2
  3. Pressure on the element reference surface. The pressure is positive in the direction opposite to the surface normal.

  1. Load ID (*DSLOAD): PNU
  2. FL−2
  3. Nonuniform pressure on the element reference surface with 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): SP (E)
  2. FL−4T2
  3. Stagnation pressure applied to the element reference surface.

  1. Load ID (*DSLOAD): TRSHR
  2. FL−2
  3. Shear traction on the element reference surface.

  1. Load ID (*DSLOAD): TRSHRNU (S)
  2. FL−2
  3. Nonuniform shear traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD.

  1. Load ID (*DSLOAD): TRVEC
  2. FL−2
  3. General traction on the element reference surface.

  1. Load ID (*DSLOAD): TRVECNU (S)
  2. FL−2
  3. Nonuniform general traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD.

  1. Load ID (*DSLOAD): VP (E)
  2. FL−3T
  3. Viscous surface pressure applied to the element reference surface. The pressure is proportional to the velocity normal to the element surface and opposing the motion.

Incident Wave Loading

Surface-based incident wave loading is also available for these elements. See Acoustic and Shock Loads.

Element Output

Output is currently available only when the surface element is used to carry rebar layers. See Defining Reinforcement for details.

Node Ordering on Elements



 

Numbering of Integration Points for Output