Products: ABAQUS/Standard ABAQUS/CAE
Coordinate 1 is 
, coordinate 2 is 
. At 
, the -direction corresponds to the global 
-direction and the -direction corresponds to the global 
-direction. This is important when data must be given in global directions. Coordinate 1 should be greater than or equal to zero.
Degree of freedom 1 is 
, degree of freedom 2 is 
. Generalized axisymmetric elements with twist have an additional degree of freedom, 5, corresponding to the twist angle 
(in radians).
ABAQUS/Standard does not automatically apply any boundary conditions to nodes located along the symmetry axis. You must apply radial or symmetry boundary conditions on these nodes if desired.
Point loads and moments should be given as the value integrated around the circumference; that is, the total value on the ring.
| Input File Usage: | Use the following option to define surface elements: |
*SURFACE SECTION If rebar are being defined, use the following option in conjunction with the *SURFACE SECTION option: *REBAR LAYER Use the following option to define a mass density per unit area: *SURFACE SECTION, DENSITY=number |
| ABAQUS/CAE Usage: | Property module: Create Section: select Shell as the section Category and Surface as the section Type, Rebar Layers (optional) |
| You cannot define the mass per unit area for a surface section in ABAQUS/CAE. |
Distributed loads are specified as described in “Distributed loads,” Section 19.4.3. Gravity and centrifugal loads apply only if the surface elements have rebar defined or if the elements have a defined density.
Load ID (*DLOAD): BR
ABAQUS/CAE Load/Interaction: Body force
Units: FL–3
Description: Body force in the radial (1 or ) direction.
Load ID (*DLOAD): BZ
ABAQUS/CAE Load/Interaction: Body force
Units: FL–3
Description: Body force in the axial (2 or ) direction.
Load ID (*DLOAD): BRNU
ABAQUS/CAE Load/Interaction: Body force
Units: FL–3
Description: Nonuniform body force in the radial direction with magnitude supplied via user subroutine DLOAD (“DLOAD,” Section 25.2.5).
Load ID (*DLOAD): BZNU
ABAQUS/CAE Load/Interaction: Body force
Units: FL–3
Description: Nonuniform body force in the axial direction with magnitude supplied via user subroutine DLOAD (“DLOAD,” Section 25.2.5).
Load ID (*DLOAD): CENT
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, 
is the angular velocity). Since only axisymmetric deformation is allowed, the spin axis must be the -axis.
Load ID (*DLOAD): CENTRIF
ABAQUS/CAE Load/Interaction: Rotational body force
Units: T–2
Description: Centrifugal load (magnitude is input as 
, where is the angular velocity). Since only axisymmetric deformation is allowed, the spin axis must be the -axis.
Load ID (*DLOAD): GRAV
ABAQUS/CAE Load/Interaction: Gravity
Units: LT–2
Description: Gravity loading in a specified direction (magnitude input as acceleration).
Load ID (*DLOAD): HP
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: Hydrostatic pressure applied to the element reference surface and linear in global 
. The pressure is positive in the direction of the positive element normal.
Load ID (*DLOAD): P
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: Pressure applied to the element reference 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 applied to the element reference surface with magnitude supplied via user subroutine DLOAD (“DLOAD,” Section 25.2.5). The pressure is positive in the direction of the positive element normal.
Load ID (*DLOAD): TRSHR
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: Shear traction on the element reference surface.
Load ID (*DLOAD): TRSHRNU(S)
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: Nonuniform shear traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD (“UTRACLOAD,” Section 25.2.41).
Load ID (*DLOAD): TRVEC
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: General traction on the element reference surface.
Load ID (*DLOAD): TRVECNU(S)
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: Nonuniform general traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD (“UTRACLOAD,” Section 25.2.41).
Foundations are specified as described in “Element foundations,” Section 2.2.2.
Load ID (*FOUNDATION): F
ABAQUS/CAE Load/Interaction: Elastic foundation
Units: FL–3
Description: Elastic foundation. For SFMGAX1 and SFMGAX2 elements the elastic foundations are applied to degrees of freedom and only.
Surface-based distributed loads are specified as described in “Distributed loads,” Section 19.4.3.
Load ID (*DSLOAD): HP
ABAQUS/CAE Load/Interaction: Pressure
Units: FL–2
Description: Hydrostatic pressure applied to the element reference surface and linear in global . 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 applied to the element reference 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 applied to the element reference surface with magnitude supplied via user subroutine DLOAD (“DLOAD,” Section 25.2.5). 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 reference surface.
Load ID (*DSLOAD): TRSHRNU(S)
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: Nonuniform shear traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD (“UTRACLOAD,” Section 25.2.41).
Load ID (*DSLOAD): TRVEC
ABAQUS/CAE Load/Interaction: Surface traction
Units: FL–2
Description: General traction on the element reference surface.
Load ID (*DSLOAD): TRVECNU(S)
ABAQUS/CAE Load/Interaction: Not supported
Units: FL–2
Description: Nonuniform general traction on the element reference surface with magnitude and direction supplied via user subroutine UTRACLOAD (“UTRACLOAD,” Section 25.2.41).
Surface-based incident wave loading is also available for these elements. See “Acoustic loads,” Section 19.4.5.
Output is currently available only when the surface element is used to carry rebar layers. See “Defining reinforcement,” Section 2.2.3, for details.
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