1, 2, 3 and two in-surface rotations for
STRI65,
S4R5,
S8R5,
S9R5 at most nodes
1, 2, 3, 4, 5, 6 for STRI65,
S4R5,
S8R5,
S9R5 at any node that
has a boundary condition on a rotational degree of freedom;
is involved in a multi-point constraint that uses rotational degrees of freedom;
is attached to a beam or to a shell element that uses six degrees of freedom at all
nodes (such as S4R,
S8R,
STRI3, etc.);
is a point where different elements have different surface normals (user-specified
normal definitions or normal definitions created by Abaqus because the surface is folded); or
is loaded with moments.
Additional Solution Variables
Element type S8R5 has three displacement
and two rotation variables at an internally generated midbody node.
8-node thick shell, biquadratic displacement, bilinear temperature in the shell
surface
Active Degrees of Freedom
1, 2, 3, 4, 5, 6 at all nodes
11, 12, 13, etc. (temperatures through the thickness as described in Choosing a Shell Element) at all nodes for
S3T,
S3RT,
S4T, and
S4RT; and at the corner nodes only for
S8RT
Additional Solution Variables
None.
Nodal Coordinates Required
and, optionally for shells with displacement degrees of freedom in Abaqus/Standard, , the direction cosines of the shell normal at the node.
Element Property Definition
Input File Usage
Use either of the following options for stress/displacement elements:
Property module: Create Section: select Shell as the section Category and Homogeneous or Composite as the section Type
Element-Based Loading
Distributed Loads
Distributed loads are available for all elements with displacement degrees of
freedom. They are specified as described in Distributed Loads.
Body forces, centrifugal loads, and Coriolis forces must be given as force per unit
area if the equivalent section properties are specified directly as part of the general
shell section definition.
*dload
Load ID (*DLOAD): BX
Body force
FL−3
Body force (give magnitude as force per unit volume) in the global
X-direction.
Load ID (*DLOAD): BY
Body force
FL−3
Body force (give magnitude as force per unit volume) in the global
Y-direction.
Load ID (*DLOAD): BZ
Body force
FL−3
Body force (give magnitude as force per unit volume) in the global
Z-direction.
Load ID (*DLOAD): BXNU
Body force
FL−3
Nonuniform body force (give magnitude as force per unit volume) in the global
X-direction, with magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit.
Load ID (*DLOAD): BYNU
Body force
FL−3
Nonuniform body force (give magnitude as force per unit volume) in the global
Y-direction, with magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit.
Load ID (*DLOAD): BZNU
Body force
FL−3
Nonuniform body force (give magnitude as force per unit volume) in the global
Z-direction, with magnitude supplied via user subroutine DLOAD in Abaqus/Standard and VDLOAD in Abaqus/Explicit.
Load ID (*DLOAD): CENT(S)
Not supported
FL−4 (ML−3T−2)
Centrifugal load (magnitude defined as , where is the mass density and is the angular speed).
Load ID (*DLOAD): CENTRIF(S)
Rotational body force
T−2
Centrifugal load (magnitude is input as , where is the angular speed).
Load ID (*DLOAD): CORIO(S)
Coriolis force
FL−4T (ML−3T−1)
Coriolis force (magnitude input , where is the mass density and is the angular speed). The load stiffness due to Coriolis loading
is not accounted for in direct steady-state dynamics analysis.
Load ID (*DLOAD): EDLDn
Shell edge load
FL−1
General traction on edge n.
Load ID (*DLOAD): EDLDnNU(S)
Not supported
FL−1
Nonuniform general traction on edge n with magnitude and
direction supplied via user subroutine UTRACLOAD.
Load ID (*DLOAD): EDMOMn
Shell edge load
F
Moment on edge n.
Load ID (*DLOAD): EDMOMnNU(S)
Not supported
F
Nonuniform moment on edge n with magnitude supplied via
user subroutine UTRACLOAD.
Load ID (*DLOAD): EDNORn
Shell edge load
FL−1
Normal traction on edge n.
Load ID (*DLOAD): EDNORnNU(S)
Not supported
FL−1
Nonuniform normal traction on edge n with magnitude
supplied via user subroutine UTRACLOAD.
Load ID (*DLOAD): EDSHRn
Shell edge load
FL−1
Shear traction on edge n.
Load ID (*DLOAD): EDSHRnNU(S)
Not supported
FL−1
Nonuniform shear traction on edge n with magnitude
supplied via user subroutine UTRACLOAD.
Load ID (*DLOAD): EDTRAn
Shell edge load
FL−1
Transverse traction on edge n.
Load ID (*DLOAD): EDTRAnNU(S)
Not supported
FL−1
Nonuniform transverse traction on edge n with magnitude
supplied via user subroutine UTRACLOAD.
Load ID (*DLOAD): GRAV
Gravity
LT−2
Gravity loading in a specified direction (magnitude is input as acceleration).
Load ID (*DLOAD): HP(S)
Not supported
FL−2
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.
Load ID (*DLOAD): P
Pressure
FL−2
Pressure applied to the element reference surface. The pressure is positive in the
direction of the positive element normal.
Load ID (*DLOAD): PNU
Not supported
FL−2
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.
Load ID (*DLOAD): ROTA(S)
Rotational body force
T−2
Rotary acceleration load (magnitude is input as , where is the rotary acceleration).
Load ID (*DLOAD): ROTDYNF(S)
Not supported
T−1
Rotordynamic load (magnitude is input as , where is the angular velocity).
Load ID (*DLOAD): SBF(E)
Not supported
FL−5T
Stagnation body force in global X-, Y-,
and Z-directions.
Load ID (*DLOAD): SP(E)
Not supported
FL−4T2
Stagnation pressure applied to the element reference surface.
Load ID (*DLOAD): TRSHR
Surface traction
FL−2
Shear traction on the element reference surface.
Load ID (*DLOAD): TRSHRNU(S)
Not supported
FL−2
Nonuniform shear traction on the element reference surface with magnitude and
direction supplied via user subroutine UTRACLOAD.
Load ID (*DLOAD): TRVEC
Surface traction
FL−2
General traction on the element reference surface.
Load ID (*DLOAD): TRVECNU(S)
Not supported
FL−2
Nonuniform general traction on the element reference surface with magnitude and
direction supplied via user subroutine UTRACLOAD.
Load ID (*DLOAD): VBF(E)
Not supported
FL−4T
Viscous body force in global X-, Y-, and
Z-directions.
Load ID (*DLOAD): VP(E)
Not supported
FL−3T
Viscous surface pressure. The viscous pressure is proportional to the velocity
normal to the element 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.
*foundation
Load ID (*FOUNDATION): F(S)
Elastic foundation
FL−3
Elastic foundation in the direction of the shell normal.
Distributed Heat Fluxes
Distributed heat fluxes are available for elements with temperature degrees of
freedom. They are specified as described in Thermal Loads.
*dflux
Load ID (*DFLUX): BF(S)
Body heat flux
JL−3 T−1
Body heat flux per unit volume.
Load ID (*DFLUX): BFNU(S)
Body heat flux
JL−3 T−1
Nonuniform body heat flux per unit volume with magnitude supplied via user
subroutine DFLUX.
Load ID (*DFLUX): MBFNU(S)
Not supported
JT−1
Nonuniform moving or stationary concentrated heat fluxes with magnitudes supplied
via user subroutine UMDFLUX.
Load ID (*DFLUX): SNEG(S)
Surface heat flux
JL−2 T−1
Surface heat flux per unit area into the bottom face of the element.
Load ID (*DFLUX): SPOS(S)
Surface heat flux
JL−2 T−1
Surface heat flux per unit area into the top face of the element.
Load ID (*DFLUX): SNEGNU(S)
Not supported
JL−2 T−1
Nonuniform surface heat flux per unit area into the bottom face of the element with
magnitude supplied via user subroutine DFLUX.
Load ID (*DFLUX): SPOSNU(S)
Not supported
JL−2 T−1
Nonuniform surface heat flux per unit area into the top face of the element with
magnitude supplied via user subroutine DFLUX.
Film Conditions
Film conditions are available for elements with temperature degrees of freedom. They
are specified as described in Thermal Loads.
*film
Load ID (*FILM): FNEG(S)
Surface film condition
JL−2 T−1−1
Film coefficient and sink temperature (units of ) provided on the bottom face of the element.
Load ID (*FILM): FPOS(S)
Surface film condition
JL−2 T−1−1
Film coefficient and sink temperature (units of ) provided on the top face of the element.
Load ID (*FILM): FNEGNU(S)
Not supported
JL−2 T−1−1
Nonuniform film coefficient and sink temperature (units of ) provided on the bottom face of the element with magnitude
supplied via user subroutine FILM.
Load ID (*FILM): FPOSNU(S)
Not supported
JL−2 T−1−1
Nonuniform film coefficient and sink temperature (units of ) provided on the top face of the element with magnitude supplied
via user subroutine FILM.
Load ID (*FILM): FFS(S)
Surface film condition
JL−2 T−1−1
Film coefficient and sink temperature (units of ) provided on the top and bottom faces of the element.
Load ID (*FILM): FFSNU(S)
Surface film condition
JL−2 T−1−1
Nonuniform film coefficient and sink temperature (units of ) provided on the top and bottom faces of the element with
magnitude supplied via user subroutine.
Radiation Types
Radiation conditions are available for elements with temperature degrees of freedom.
They are specified as described in Thermal Loads.
*radiate
Load ID (*RADIATE): RNEG(S)
Surface radiation
Dimensionless
Emissivity and sink temperature (units of ) provided for the bottom face of the shell.
Load ID (*RADIATE): RPOS(S)
Surface radiation
Dimensionless
Emissivity and sink temperature (units of ) provided for the top face of the shell.
Load ID (*RADIATE): RFS(S)
Surface radiation
Dimensionless
Emissivity and sink temperature (units of ) provided for the top and bottom faces of the shell.
Surface-Based Loading
Distributed Loads
Surface-based distributed loads are available for all elements with displacement
degrees of freedom. They are specified as described in Distributed Loads.
*dsload
Load ID (*DSLOAD): EDLD
Shell edge load
FL−1
General traction on edge-based surface.
Load ID (*DSLOAD): EDLDNU(S)
Shell edge load
FL−1
Nonuniform general traction on edge-based surface with magnitude and direction
supplied via user subroutine UTRACLOAD.
Load ID (*DSLOAD): EDMOM
Shell edge load
F
Moment on edge-based surface.
Load ID (*DSLOAD): EDMOMNU(S)
Shell edge load
F
Nonuniform moment on edge-based surface with magnitude supplied via user subroutine
UTRACLOAD.
Load ID (*DSLOAD): EDNOR
Shell edge load
FL−1
Normal traction on edge-based surface.
Load ID (*DSLOAD): EDNORNU(S)
Shell edge load
FL−1
Nonuniform normal traction on edge-based surface with magnitude supplied via user
subroutine UTRACLOAD.
Load ID (*DSLOAD): EDSHR
Shell edge load
FL−1
Shear traction on edge-based surface.
Load ID (*DSLOAD): EDSHRNU(S)
Shell edge load
FL−1
Nonuniform shear traction on edge-based surface with magnitude supplied via user
subroutine UTRACLOAD.
Load ID (*DSLOAD): EDTRA
Shell edge load
FL−1
Transverse traction on edge-based surface.
Load ID (*DSLOAD): EDTRANU(S)
Shell edge load
FL−1
Nonuniform transverse traction on edge-based surface with magnitude supplied via
user subroutine UTRACLOAD.
Load ID (*DSLOAD): HP(S)
Pressure
FL−2
Hydrostatic pressure on the element reference surface and linear in global
Z. The pressure is positive in the direction opposite to the
surface normal.
Load ID (*DSLOAD): P
Pressure
FL−2
Pressure on the element reference surface. The pressure is positive in the
direction opposite to the surface normal.
Load ID (*DSLOAD): PNU
Pressure
FL−2
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.
Load ID (*DSLOAD): SP(E)
Pressure
FL−4T2
Stagnation pressure applied to the element reference surface.
Load ID (*DSLOAD): TRSHR
Surface traction
FL−2
Shear traction on the element reference surface.
Load ID (*DSLOAD): TRSHRNU(S)
Surface traction
FL−2
Nonuniform shear traction on the element reference surface with magnitude and
direction supplied via user subroutine UTRACLOAD.
Load ID (*DSLOAD): TRVEC
Surface traction
FL−2
General traction on the element reference surface.
Load ID (*DSLOAD): TRVECNU(S)
Surface traction
FL−2
Nonuniform general traction on the element reference surface with magnitude and
direction supplied via user subroutine UTRACLOAD.
Load ID (*DSLOAD): VP(E)
Pressure
FL−3T
Viscous surface pressure. The viscous pressure is proportional to the velocity
normal to the element face and opposing the motion.
Distributed Heat Fluxes
Surface-based distributed heat fluxes are available for elements with temperature
degrees of freedom. They are specified as described in Thermal Loads.
*dsflux
Load ID (*DSFLUX): S(S)
Surface heat flux
JL−2 T−1
Surface heat flux per unit area into the element surface.
Load ID (*DSFLUX): SNU(S)
Surface heat flux
JL−2 T−1
Nonuniform surface heat flux per unit area into the element surface with magnitude
supplied via user subroutine DFLUX.
Film Conditions
Surface-based film conditions are available for elements with temperature degrees of
freedom. They are specified as described in Thermal Loads.
*sfilm
Load ID (*SFILM): F(S)
Surface film condition
JL−2 T−1−1
Film coefficient and sink temperature (units of ) provided on the element surface.
Load ID (*SFILM): FNU(S)
Surface film condition
JL−2 T−1−1
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 elements with temperature
degrees of freedom. They are specified as described in Thermal Loads.
*sradiate
Load ID (*SRADIATE): R(S)
Surface radiation
Dimensionless
Emissivity and sink temperature (units of ) provided for the element surface.
Incident Wave Loading
Surface-based incident wave loads are available. They are specified as described in
Coupled Acoustic-Structural Analysis. If the
incident wave field includes a reflection off a plane outside the boundaries of the
mesh, this effect can be included.
Element Output
If a local coordinate system is not assigned to the element, the stress/strain
components, as well as the section forces/strains, are in the default directions on the
surface defined by the convention given in Conventions. If a local
coordinate system is assigned to the element through the section definition (Orientations), the
stress/strain components and the section forces/strains are in the surface directions
defined by the local coordinate system.
In large-displacement problems with elements that allow finite membrane strains in Abaqus/Standard and in all problems in Abaqus/Explicit, the local directions defined in the reference configuration are rotated into the
current configuration by the average material rotation.
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
Local direct stress.
S22
Local direct stress.
S12
Local shear stress.
Section Forces, Moments, and Transverse Shear Forces
Available for elements with displacement degrees of freedom.
SF1
Direct membrane force per unit width in local 1-direction.
SF2
Direct membrane force per unit width in local 2-direction.
SF3
Shear membrane force per unit width in local 1–2 plane.
SF4
Transverse shear force per unit width in local 1-direction (available only for
S3/S3R,
S3RS,
S4,
S4R,
S4RS,
S4RSW,
S8R, and
S8RT).
SF5
Transverse shear force per unit width in local 2-direction (available only for
S3/S3R,
S3RS,
S4,
S4R,
S4RS,
S4RSW,
S8R, and
S8RT).
SM1
Bending moment force per unit width about local 2-axis.
SM2
Bending moment force per unit width about local 1-axis.
SM3
Twisting moment force per unit width in local 1–2 plane.
The section force and moment resultants per unit length in the normal basis directions
in a given shell section of thickness h can be defined on this
basis as
where is the offset of the reference surface from the midsurface.
The section force SF6, which is the
integral of through the shell thickness, is reported only for finite-strain shell
elements and is zero because of the plane stress constitutive assumption. The total
number of attributes written to the results file for finite-strain shell elements is 9;
SF6 is the sixth attribute.
Average Section Stresses
Available for elements with displacement degrees of freedom.
SSAVG1
Average membrane stress in local 1-direction.
SSAVG2
Average membrane stress in local 2-direction.
SSAVG3
Average membrane stress in local 1–2 plane.
SSAVG4
Average transverse shear stress in local 1-direction.
SSAVG5
Average transverse shear stress in local 2-direction.
The average section stresses are defined as
where h is the current section thickness.
Section Strains, Curvatures, and Transverse Shear Strains
Available for elements with displacement degrees of freedom.
SE1
Direct membrane strain in local 1-direction.
SE2
Direct membrane strain in local 2-direction.
SE3
Shear membrane strain in local 1–2 plane.
SE4
Transverse shear strain in the local 1-direction (available only for
S3/S3R,
S3RS,
S4,
S4R,
S4RS,
S4RSW,
S8R, and
S8RT).
SE5
Transverse shear strain in the local 2-direction (available only for
S3/S3R,
S3RS,
S4,
S4R,
S4RS,
S4RSW,
S8R, and
S8RT).
SE6
Strain in the thickness direction (available only for
S3/S3R,
S3RS,
S4,
S4R,
S4RS, and
S4RSW).
Shell thickness, which is the current section thickness for
S3/S3R,
S3RS,
S4,
S4R,
S4RS, and
S4RSW elements.
Transverse Shear Stress Estimates
Available for
S3/S3R,
S3RS,
S4,
S4R,
S4RS,
S4RSW,
S8R, and
S8RT elements.
TSHR13
13-component of transverse shear stress.
TSHR23
23-component of transverse shear stress.
Estimates of the transverse shear stresses are available at section integration points
as output variables TSHR13 or
TSHR23 for both Simpson's rule and
Gauss quadrature. For Simpson's rule output of variables
TSHR13 or
TSHR23 should be requested at
nondefault section points, since the default output is at section point 1 of the shell
section where the transverse shear stresses vanish. For the small-strain elements in Abaqus/Explicit, transverse shear stress distributions are assumed constant for noncomposite sections
and piecewise constant for composite sections; therefore, transverse shear stresses at
integration points should be interpreted accordingly.
For element type S4 the transverse shear
calculation is performed at the center of the element and assumed constant over the
element. Hence, transverse shear strain, force, and stress will not vary over the area
of the element.
For numerically integrated shell sections (with the exception of small-strain shells in
Abaqus/Explicit), estimates of the interlaminar shear stresses in composite sections—i.e., the
transverse shear stresses at the interface between two composite layers—can be obtained
only by using Simpson's rule. With Gauss quadrature no section integration point exists
at the interface between composite layers.
Unlike the S11,
S22, and
S12 in-plane stress components,
transverse shear stress components
TSHR13 and
TSHR23 are not calculated from the
constitutive behavior at points through the shell section. They are estimated by
matching the elastic strain energy associated with shear deformation of the shell
section with that based on piecewise quadratic variation of the transverse shear stress
across the section, under conditions of bending about one axis (see Transverse shear stiffness in composite shells and offsets from the midsurface). Therefore,
interlaminar shear stress calculation is supported only when each layer of the shell
section is defined using an elastic material model or a user-defined material model with
the elastic transverse shear moduli defined. If you specify the transverse shear
stiffness values, interlaminar shear stress output is not available.
Heat Flux Components
Available for elements with temperature degrees of freedom.