22.1.4 Three-dimensional solid element library

**Products: **ABAQUS/Standard ABAQUS/Explicit ABAQUS/CAE

Stress/displacement elements

C3D4 | 4-node linear tetrahedron |

C3D4H^{(S)} | 4-node linear tetrahedron, hybrid with constant pressure |

C3D6 | 6-node linear triangular prism |

C3D6H^{(S)} | 6-node linear triangular prism, hybrid with constant pressure |

C3D8^{(S)} | 8-node linear brick |

C3D8H^{(S)} | 8-node linear brick, hybrid with constant pressure |

C3D8I^{(S)} | 8-node linear brick, incompatible modes |

C3D8IH^{(S)} | 8-node linear brick, incompatible modes, hybrid with linear pressure |

C3D8R | 8-node linear brick, reduced integration with hourglass control |

C3D8RH^{(S)} | 8-node linear brick, reduced integration with hourglass control, hybrid with constant pressure |

C3D10^{(S)} | 10-node quadratic tetrahedron |

C3D10H^{(S)} | 10-node quadratic tetrahedron, hybrid with linear pressure |

C3D10M | 10-node modified tetrahedron, with hourglass control |

C3D10MH^{(S)} | 10-node modified tetrahedron, with hourglass control, hybrid with linear pressure |

C3D15^{(S)} | 15-node quadratic triangular prism |

C3D15H^{(S)} | 15-node quadratic triangular prism, hybrid with linear pressure |

C3D20^{(S)} | 20-node quadratic brick |

C3D20H^{(S)} | 20-node quadratic brick, hybrid with linear pressure |

C3D20R^{(S)} | 20-node quadratic brick, reduced integration |

C3D20RH^{(S)} | 20-node quadratic brick, reduced integration, hybrid with linear pressure |

The constant pressure hybrid elements have one additional variable relating to pressure, and the linear pressure hybrid elements have four additional variables relating to pressure.

Element types C3D8I and C3D8IH have thirteen additional variables relating to the incompatible modes.

Element types C3D10M and C3D10MH have three additional displacement variables.

Stress/displacement variable node elements

C3D15V^{(S)} | 15 to 18-node triangular prism |

C3D15VH^{(S)} | 15 to 18-node triangular prism, hybrid with linear pressure |

C3D27^{(S)} | 21 to 27-node brick |

C3D27H^{(S)} | 21 to 27-node brick, hybrid with linear pressure |

C3D27R^{(S)} | 21 to 27-node brick, reduced integration |

C3D27RH^{(S)} | 21 to 27-node brick, reduced integration, hybrid with linear pressure |

Coupled temperature-displacement elements

C3D4T^{(E)} | 4-node linear displacement and temperature |

C3D6T^{(E)} | 6-node linear displacement and temperature |

C3D8T^{(S)} | 8-node trilinear displacement and temperature |

C3D8HT^{(S)} | 8-node trilinear displacement and temperature, hybrid with constant pressure |

C3D8RT | 8-node trilinear displacement and temperature, reduced integration with hourglass control |

C3D8RHT^{(S)} | 8-node trilinear displacement and temperature, reduced integration with hourglass control, hybrid with constant pressure |

C3D10MT | 10-node modified displacement and temperature tetrahedron, with hourglass control |

C3D10MHT^{(S)} | 10-node modified displacement and temperature tetrahedron, with hourglass control, hybrid with linear pressure |

C3D20T^{(S)} | 20-node triquadratic displacement, trilinear temperature |

C3D20HT^{(S)} | 20-node triquadratic displacement, trilinear temperature, hybrid with linear pressure |

C3D20RT^{(S)} | 20-node triquadratic displacement, trilinear temperature, reduced integration |

C3D20RHT^{(S)} | 20-node triquadratic displacement, trilinear temperature, reduced integration, hybrid with linear pressure |

1, 2, 3, 11 at corner nodes

1, 2, 3 at midside nodes of second-order elements in ABAQUS/Standard

1, 2, 3, 11 at midside nodes of modified displacement and temperature elements in ABAQUS/Standard

The constant pressure hybrid element has one additional variable relating to pressure, and the linear pressure hybrid elements have four additional variables relating to pressure.

Element types C3D10MT and C3D10MHT have three additional displacement variables and one additional temperature variable.

Diffusive heat transfer or mass diffusion elements

DC3D4^{(S)} | 4-node linear tetrahedron |

DC3D6^{(S)} | 6-node linear triangular prism |

DC3D8^{(S)} | 8-node linear brick |

DC3D10^{(S)} | 10-node quadratic tetrahedron |

DC3D15^{(S)} | 15-node quadratic triangular prism |

DC3D20^{(S)} | 20-node quadratic brick |

Coupled thermal-electrical elements

DC3D4E^{(S)} | 4-node linear tetrahedron |

DC3D6E^{(S)} | 6-node linear triangular prism |

DC3D8E^{(S)} | 8-node linear brick |

DC3D10E^{(S)} | 10-node quadratic tetrahedron |

DC3D15E^{(S)} | 15-node quadratic triangular prism |

DC3D20E^{(S)} | 20-node quadratic brick |

Pore pressure elements

C3D8P^{(S)} | 8-node trilinear displacement and pore pressure |

C3D8PH^{(S)} | 8-node trilinear displacement and pore pressure, hybrid with constant pressure |

C3D8RP^{(S)} | 8-node trilinear displacement and pore pressure, reduced integration |

C3D8RPH^{(S)} | 8-node trilinear displacement and pore pressure, reduced integration, hybrid with constant pressure |

C3D10MP^{(S)} | 10-node modified displacement and pore pressure tetrahedron, with hourglass control |

C3D10MPH^{(S)} | 10-node modified displacement and pore pressure tetrahedron, with hourglass control, hybrid with linear pressure |

C3D20P^{(S)} | 20-node triquadratic displacement, trilinear pore pressure |

C3D20PH^{(S)} | 20-node triquadratic displacement, trilinear pore pressure, hybrid with linear pressure |

C3D20RP^{(S)} | 20-node triquadratic displacement, trilinear pore pressure, reduced integration |

C3D20RPH^{(S)} | 20-node triquadratic displacement, trilinear pore pressure, reduced integration, hybrid with linear pressure |

1, 2, 3 at midside nodes for all elements except C3D10MP and C3D10MPH, which also have degree of freedom 8 active at midside nodes

1, 2, 3, 8 at corner nodes

The constant pressure hybrid elements have one additional variable relating to the effective pressure stress, and the linear pressure hybrid elements have four additional variables relating to the effective pressure stress to permit fully incompressible material modeling.

Element types C3D10MP and C3D10MPH have three additional displacement variables and one additional pore pressure variable.

Acoustic elements

AC3D4 | 4-node linear tetrahedron |

AC3D6 | 6-node linear triangular prism |

AC3D8^{(S)} | 8-node linear brick |

AC3D8R^{(E)} | 8-node linear brick, reduced integration with hourglass control |

AC3D10^{(S)} | 10-node quadratic tetrahedron |

AC3D15^{(S)} | 15-node quadratic triangular prism |

AC3D20^{(S)} | 20-node quadratic brick |

Piezoelectric elements

C3D4E^{(S)} | 4-node linear tetrahedron |

C3D6E^{(S)} | 6-node linear triangular prism |

C3D8E^{(S)} | 8-node linear brick |

C3D10E^{(S)} | 10-node quadratic tetrahedron |

C3D15E^{(S)} | 15-node quadratic triangular prism |

C3D20E^{(S)} | 20-node quadratic brick |

C3D20RE^{(S)} | 20-node quadratic brick, reduced integration |

Input File Usage: | *SOLID SECTION |

ABAQUS/CAE Usage: | Property module: |

Distributed loads

Distributed loads are available for all elements with displacement degrees of freedom. They are specified as described in “Distributed loads,” Section 27.4.3.

**Load ID (*DLOAD):** BX**ABAQUS/CAE Load/Interaction:** **Body force****Units:** FL^{–3}**Description: **Body force in global *X*-direction.

**Load ID (*DLOAD):** BY**ABAQUS/CAE Load/Interaction:** **Body force****Units:** FL^{–3}**Description: **Body force in global *Y*-direction.

**Load ID (*DLOAD):** BZ**ABAQUS/CAE Load/Interaction:** **Body force****Units:** FL^{–3}**Description: **Body force in global *Z*-direction.

**Load ID (*DLOAD):** BXNU**ABAQUS/CAE Load/Interaction:** **Body force****Units:** FL^{–3}**Description: **Nonuniform body force in global *X*-direction with magnitude supplied via user subroutine `DLOAD` in ABAQUS/Standard and `VDLOAD` in ABAQUS/Explicit.

**Load ID (*DLOAD):** BYNU**ABAQUS/CAE Load/Interaction:** **Body force****Units:** FL^{–3}**Description: **Nonuniform body force in global *Y*-direction with magnitude supplied via user subroutine `DLOAD` in ABAQUS/Standard and `VDLOAD` in ABAQUS/Explicit.

**Load ID (*DLOAD):** BZNU**ABAQUS/CAE Load/Interaction:** **Body force****Units:** FL^{–3}**Description: **Nonuniform body force in global *Z*-direction with magnitude supplied via user subroutine `DLOAD` in ABAQUS/Standard and `VDLOAD` in ABAQUS/Explicit.

**Load ID (*DLOAD):** CENT^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–4}(ML^{–3}T^{–2})**Description: **Centrifugal load (magnitude is input as , where is the mass density per unit volume, is the angular velocity). Not available for pore pressure elements.

**Load ID (*DLOAD):** CENTRIF^{(S)}**ABAQUS/CAE Load/Interaction:** **Rotational body force****Units:** T^{–2}**Description: **Centrifugal load (magnitude is input as , where is the angular velocity).

**Load ID (*DLOAD):** CORIO^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–4}T (ML^{–3}T^{–1})**Description: **Coriolis force (magnitude is input as , where is the mass density per unit volume, is the angular velocity). Not available for pore pressure elements.

**Load ID (*DLOAD):** GRAV**ABAQUS/CAE Load/Interaction:** **Gravity****Units:** LT^{–2}**Description: **Gravity loading in a specified direction (magnitude is input as acceleration).

**Load ID (*DLOAD):** HP*n*^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–2}**Description: **Hydrostatic pressure on face *n*, linear in global *Z*.

**Load ID (*DLOAD):** P*n***ABAQUS/CAE Load/Interaction:** **Pressure****Units:** FL^{–2}**Description: **Pressure on face *n*.

**Load ID (*DLOAD):** P*n*NU**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–2}**Description: **Nonuniform pressure on face *n* with magnitude supplied via user subroutine `DLOAD` in ABAQUS/Standard and `VDLOAD` in ABAQUS/Explicit.

**Load ID (*DLOAD):** ROTA^{(S)}**ABAQUS/CAE Load/Interaction:** **Rotational body force****Units:** T^{–2}**Description: **Rotary acceleration load (magnitude is input as , where is the rotary acceleration).

**Load ID (*DLOAD):** SBF^{(E)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–5}T^{2}**Description: **Stagnation body force in global *X*-, *Y*-, and *Z*-directions.

**Load ID (*DLOAD):** SP*n*^{(E)}**ABAQUS/CAE Load/Interaction:** **Pressure****Units:** FL^{–4}T^{2}**Description: **Stagnation pressure on face *n*.

**Load ID (*DLOAD):** TRSHR*n***ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–2}**Description: **Shear traction on face *n*.

**Load ID (*DLOAD):** TRSHR*n*NU^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–2}**Description: **Nonuniform shear traction on face *n* with magnitude and direction supplied via user subroutine `UTRACLOAD`.

**Load ID (*DLOAD):** TRVEC*n***ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–2}**Description: **General traction on face *n*.

**Load ID (*DLOAD):** TRVEC*n*NU^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–2}**Description: **Nonuniform general traction on face *n* with magnitude and direction supplied via user subroutine `UTRACLOAD`.

**Load ID (*DLOAD):** VBF^{(E)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** FL^{–4}T**Description: **Viscous body force in global *X*-, *Y*-, and *Z*-directions.

**Load ID (*DLOAD):** VP*n*^{(E)}**ABAQUS/CAE Load/Interaction:** **Pressure****Units:** FL^{–3}T**Description: **Viscous pressure on face *n*, applying a pressure proportional to the velocity normal to the face and opposing the motion.

Foundations

Foundations are available for ABAQUS/Standard elements with displacement degrees of freedom. They are specified as described in “Element foundations,” Section 2.2.2.

**Load ID (*FOUNDATION):** F*n*^{(S)}**ABAQUS/CAE Load/Interaction:** **Elastic foundation****Units:** FL^{–3}**Description: **Elastic foundation on face *n*.

Distributed heat fluxes

Distributed heat fluxes are available for all elements with temperature degrees of freedom. They are specified as described in “Thermal loads,” Section 27.4.4.

**Load ID (*DFLUX):** BF**ABAQUS/CAE Load/Interaction:** **Body heat flux****Units:** JL^{–3}T^{–1}**Description: **Heat body flux per unit volume.

**Load ID (*DFLUX):** BFNU^{(S)}**ABAQUS/CAE Load/Interaction:** **Body heat flux****Units:** JL^{–3}T^{–1}**Description: **Nonuniform heat body flux per unit volume with magnitude supplied via user subroutine `DFLUX`.

**Load ID (*DFLUX):** S*n***ABAQUS/CAE Load/Interaction:** Not supported**Units:** JL^{–2}T^{–1}**Description: **Heat surface flux per unit area into face *n*.

**Load ID (*DFLUX):** S*n*NU^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** JL^{–2}T^{–1}**Description: **Nonuniform heat surface flux per unit area into face *n* with magnitude supplied via user subroutine `DFLUX`.

Film conditions

Film conditions are available for all elements with temperature degrees of freedom. They are specified as described in “Thermal loads,” Section 27.4.4.

**Load ID (*FILM):** F*n***ABAQUS/CAE Load/Interaction:** **Surface film condition****Units:** JL^{–2}T^{–1}^{–1}**Description: **Film coefficient and sink temperature (units of ) provided on face *n*.

**Load ID (*FILM):** F*n*NU^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** JL^{–2}T^{–1}^{–1}**Description: **Nonuniform film coefficient and sink temperature (units of ) provided on face *n* with magnitude supplied via user subroutine `FILM`.

Radiation types

Radiation conditions are available for all elements with temperature degrees of freedom. They are specified as described in “Thermal loads,” Section 27.4.4.

**Load ID (*RADIATE):** R*n***ABAQUS/CAE Load/Interaction:** Not supported**Units:** Dimensionless**Description: **Emissivity and sink temperature (units of ) provided on face *n*.

Distributed flows

Distributed flows are available for all elements with pore pressure degrees of freedom. They are specified as described in “Pore fluid flow,” Section 27.4.6.

**Load ID (*FLOW/ *DFLOW):** Q*n*^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** F^{–1}L^{3}T^{–1}**Description: **Seepage (outward normal flow) proportional to the difference between surface pore pressure and a reference sink pore pressure on face *n* (units of FL^{–2}).

**Load ID (*FLOW/ *DFLOW):** Q*n*D^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** F^{–1}L^{3}T^{–1}**Description: **Drainage-only seepage (outward normal flow) proportional to the surface pore pressure on face *n* only when that pressure is positive.

**Load ID (*FLOW/ *DFLOW):** Q*n*NU^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** F^{–1}L^{3}T^{–1}**Description: **Nonuniform seepage (outward normal flow) proportional to the difference between surface pore pressure and a reference sink pore pressure on face *n* (units of FL^{–2}) with magnitude supplied via user subroutine `FLOW`.

**Load ID (*FLOW/ *DFLOW):** S*n*^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** LT^{–1}**Description: **Prescribed pore fluid effective velocity (outward from the face) on face *n*.

**Load ID (*FLOW/ *DFLOW):** S*n*NU^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** LT^{–1}**Description: **Nonuniform prescribed pore fluid effective velocity (outward from the face) on face *n* with magnitude supplied via user subroutine `DFLOW`.

Distributed impedances

Distributed impedances are available for all elements with acoustic pressure degrees of freedom. They are specified as described in “Acoustic loads,” Section 27.4.5.

**Load ID (*IMPEDANCE):** I*n***ABAQUS/CAE Load/Interaction:** Not supported**Units:** None**Description: **Name of the impedance property that defines the impedance on face *n*.

Electric fluxes

Electric fluxes are available for piezoelectric elements. They are specified as described in “Piezoelectric analysis,” Section 6.6.3.

**Load ID (*DECHARGE):** EBF^{(S)}**ABAQUS/CAE Load/Interaction:** **Body charge****Units:** CL^{–3}**Description: **Body flux per unit volume.

**Load ID (*DECHARGE):** ES*n*^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** CL^{–2}**Description: **Prescribed surface charge on face *n*.

Distributed electric current densities

Distributed electric current densities are available for coupled thermal-electrical elements. They are specified as described in “Coupled thermal-electrical analysis,” Section 6.6.2.

**Load ID (*DECURRENT):** CBF^{(S)}**ABAQUS/CAE Load/Interaction:** **Body current****Units:** CL^{–3}T^{–1}**Description: **Volumetric current source density.

**Load ID (*DECURRENT):** CS*n*^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** CL^{–2}T^{–1}**Description: **Current density on face *n*.

Distributed concentration fluxes

Distributed concentration fluxes are available for mass diffusion elements. They are specified as described in “Mass diffusion analysis,” Section 6.8.1.

**Load ID (*DFLUX):** BF^{(S)}**ABAQUS/CAE Load/Interaction:** **Body concentration flux ****Units:** PT^{–1}**Description: **Concentration body flux per unit volume.

**Load ID (*DFLUX):** BFNU^{(S)}**ABAQUS/CAE Load/Interaction:** **Body concentration flux****Units:** PT^{–1}**Description: **Nonuniform concentration body flux per unit volume with magnitude supplied via user subroutine `DFLUX`.

**Load ID (*DFLUX):** S*n*^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface concentration flux****Units:** PLT^{–1}**Description: **Concentration surface flux per unit area into face *n*.

**Load ID (*DFLUX):** S*n*NU^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface concentration flux****Units:** PLT^{–1}**Description: **Nonuniform concentration surface flux per unit area into face *n* with magnitude supplied via user subroutine `DFLUX`.

Distributed loads

Surface-based distributed loads are available for all elements with displacement degrees of freedom. They are specified as described in “Distributed loads,” Section 27.4.3.

**Load ID (*DSLOAD):** HP^{(S)}**ABAQUS/CAE Load/Interaction:** **Pressure****Units:** FL^{–2}**Description: **Hydrostatic pressure on the element surface, linear in global *Z*.

**Load ID (*DSLOAD):** P**ABAQUS/CAE Load/Interaction:** **Pressure****Units:** FL^{–2}**Description: **Pressure on the element surface.

**Load ID (*DSLOAD):** PNU**ABAQUS/CAE Load/Interaction:** **Pressure****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.

**Load ID (*DSLOAD):** SP^{(E)}**ABAQUS/CAE Load/Interaction:** **Pressure****Units:** FL^{–4}T^{2}**Description: **Stagnation pressure on the element surface.

**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:** Not supported**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:** Not supported**Units:** FL^{–2}**Description: **Nonuniform general traction on the element surface with magnitude and direction supplied via user subroutine `UTRACLOAD`.

**Load ID (*DSLOAD):** VP^{(E)}**ABAQUS/CAE Load/Interaction:** **Pressure****Units:** FL^{–3}T**Description: **Viscous pressure applied on the element surface. The viscous pressure is proportional to the velocity normal to the element face and opposing the motion.

Distributed heat fluxes

Surface-based heat fluxes are available for all elements with temperature degrees of freedom. They are specified as described in “Thermal loads,” Section 27.4.4.

**Load ID (*DSFLUX):** S**ABAQUS/CAE Load/Interaction:** **Surface heat flux****Units:** JL^{–2}T^{–1}**Description: **Heat surface flux per unit area into the element surface.

**Load ID (*DSFLUX):** SNU^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface heat flux****Units:** JL^{–2}T^{–1}**Description: **Nonuniform heat surface flux per unit area into the element surface with magnitude supplied via user subroutine `DFLUX`.

Film conditions

Surface-based film conditions are available for all elements with temperature degrees of freedom. They are specified as described in “Thermal loads,” Section 27.4.4.

**Load ID (*SFILM):** F**ABAQUS/CAE Load/Interaction:** **Surface film condition****Units:** JL^{–2}T^{–1}^{–1}**Description: **Film coefficient and sink temperature (units of ) provided on the element surface.

**Load ID (*SFILM):** FNU^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface film condition****Units:** JL^{–2}T^{–1}^{–1}**Description: **Nonuniform film coefficient and sink temperature (units of ) provided on the element surface with magnitude supplied via user subroutine `FILM`.

Radiation types

Surface-based radiation conditions are available for all elements with temperature degrees of freedom. They are specified as described in “Thermal loads,” Section 27.4.4.

**Load ID (*SRADIATE):** R**ABAQUS/CAE Load/Interaction:** **Surface radiation to ambient****Units:** Dimensionless**Description: **Emissivity and sink temperature (units of ) provided on the element surface.

Distributed flows

Surface-based flows are available for all elements with pore pressure degrees of freedom. They are specified as described in “Pore fluid flow,” Section 27.4.6.

**Load ID (*SFLOW/ *DSFLOW):** Q^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** F^{–1}L^{3}T^{–1}**Description: **Seepage (outward normal flow) proportional to the difference between surface pore pressure and a reference sink pore pressure on the element surface (units of FL^{–2}).

**Load ID (*SFLOW/ *DSFLOW):** QD^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** F^{–1}L^{3}T^{–1}**Description: **Drainage-only seepage (outward normal flow) proportional to the surface pore pressure on the element surface only when that pressure is positive.

**Load ID (*SFLOW/ *DSFLOW):** QNU^{(S)}**ABAQUS/CAE Load/Interaction:** Not supported**Units:** F^{–1}L^{3}T^{–1}**Description: **Nonuniform seepage (outward normal flow) proportional to the difference between surface pore pressure and a reference sink pore pressure on the element surface (units of FL^{–2}) with magnitude upplied via user subroutine `FLOW`.

**Load ID (*SFLOW/ *DSFLOW):** S^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface pore fluid****Units:** LT^{–1}**Description: **Prescribed pore fluid effective velocity outward from the element surface.

**Load ID (*SFLOW/ *DSFLOW):** SNU^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface pore fluid****Units:** LT^{–1}**Description: **Nonuniform prescribed pore fluid effective velocity outward from the element surface with magnitude supplied via user subroutine `DFLOW`.

Distributed impedances

Surface-based impedances are available for all elements with acoustic pressure degrees of freedom. They are specified as described in “Acoustic loads,” Section 27.4.5.

Incident wave loading

Surface-based incident wave loads are available for all elements with displacement degrees of freedom or acoustic pressure degrees of freedom. They are specified as described in “Acoustic loads,” Section 27.4.5. If the incident wave field includes a reflection off a plane outside the boundaries of the mesh, this effect can be included.

Electric fluxes

Surface-based electric fluxes are available for piezoelectric elements. They are specified as described in “Piezoelectric analysis,” Section 6.6.3.

**Load ID (*DSECHARGE):** ES^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface charge****Units:** CL^{–2}**Description: **Prescribed surface charge on the element surface.

Distributed electric current densities

Surface-based electric current densities are available for coupled thermal-electrical elements. They are specified as described in “Coupled thermal-electrical analysis,” Section 6.6.2.

**Load ID (*DSECURRENT):** CS^{(S)}**ABAQUS/CAE Load/Interaction:** **Surface current****Units:** CL^{–2}T^{–1}**Description: **Current density on the element surface.

Output is in global directions unless a local coordinate system is assigned to the element through either the section definition (“Orientations,” Section 2.2.5) or an element property assignment (“Assigning element properties on an element-by-element basis,” Section 21.1.5), in which case output is in the local coordinate system (which rotates with the motion in large-displacement analysis). See “State storage,” Section 1.5.4 of the ABAQUS Theory Manual, for details.

Stress, strain, and other tensor components

Stress and other tensors (including strain tensors) are available for elements with displacement degrees of freedom. All tensors have the same components. For example, the stress components are as follows:

S11 | , direct stress. |

S22 | , direct stress. |

S33 | , direct stress. |

S12 | , shear stress. |

S13 | , shear stress. |

S23 | , shear stress. |

Note: the order shown above is not the same as that used in user subroutine `VUMAT`.

Heat flux components

Available for elements with temperature degrees of freedom.

HFL1 | Heat flux in the |

HFL2 | Heat flux in the |

HFL3 | Heat flux in the |

Pore fluid velocity components

Available for elements with pore pressure degrees of freedom.

FLVEL1 | Pore fluid effective velocity in the |

FLVEL2 | Pore fluid effective velocity in the |

FLVEL3 | Pore fluid effective velocity in the |

Mass concentration flux components

Available for elements with normalized concentration degrees of freedom.

MFL1 | Concentration flux in the |

MFL2 | Concentration flux in the |

MFL3 | Concentration flux in the |

Electrical potential gradient

Available for elements with electrical potential degrees of freedom.

EPG1 | Electrical potential gradient in the |

EPG2 | Electrical potential gradient in the |

EPG3 | Electrical potential gradient in the |

16–18 are midface nodes on the three rectangular faces (see below for faces 1 to 5). These nodes can be omitted from an element by entering a zero or blank in the corresponding position when giving the nodes on the element. Only nodes 16–18 can be omitted.

Node 21 is located at the centroid of the element.

(nodes 22–27) are midface nodes on the six faces (see below for faces 1 to 6). These nodes can be deleted from an element by entering a zero or blank in the corresponding position when giving the nodes on the element. Only nodes 22–27 can be omitted.

This shows the scheme in the layer closest to the 1–2–3 and 1–2–3–4 faces. The integration points in the second and third layers are numbered consecutively. Multiple layers are used for composite solid elements.

For heat transfer applications a different integration scheme is used for tetrahedral and wedge elements, as described in “Triangular, tetrahedral, and wedge elements,” Section 3.2.6 of the ABAQUS Theory Manual.

For acoustic tetrahedra and wedges in ABAQUS/Standard full integration is used, so an AC3D4 element has four integration points, an AC3D6 element has six integration points, an AC3D10 element has ten integration points, and an AC3D15 element has eighteen integration points.

This shows the scheme in the layer closest to the 1–2–3 and 1–2–3–4 faces. The integration points in the second and third layers are numbered consecutively. Multiple layers are used for composite solid elements. The face nodes do not appear.

Node 21 is located at the centroid of the element.