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Abaqus/Standard
Abaqus/Explicit
Abaqus/CAE
Stress/Displacement Elements
Stress/displacement elements are used in the modeling of linear or complex nonlinear
mechanical analyses that possibly involve contact, plasticity, and/or large deformations.
Stress/displacement elements can also be used for thermal-stress analysis, where the
temperature history can be obtained from a heat transfer analysis carried out with diffusive
elements.
Analysis Types
Stress/displacement elements can be used in the following analysis types:
Active Degrees of Freedom
Stress/displacement elements have only displacement degrees of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Choosing a Stress/Displacement Element
Stress/displacement elements are available in several different element families.
Pore Pressure Elements
Pore pressure elements are provided in Abaqus/Standard for modeling fully or partially saturated fluid flow through a deforming porous medium.
The names of all pore pressure elements include the letter P (pore pressure). These elements
cannot be used with hydrostatic fluid elements.
Analysis Types
Pore pressure elements can be used in the following analysis types:
Active Degrees of Freedom
Pore pressure elements have both displacement and pore pressure degrees of freedom. In
second-order elements the pore pressure degrees of freedom are active only at the corner
nodes. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
These elements use either linear- or second-order (quadratic) interpolation for the
geometry and displacements in two or three directions. The pore pressure is interpolated
linearly from the corner nodes. Curved element edges should be avoided; exact linear
spatial pore pressure variations cannot be obtained with curved edges.
For output purposes, the pore pressure at the midside nodes of second-order elements is
determined by linear interpolation from the corner nodes.
Choosing a Pore Pressure Element
Pore pressure elements are available only in the following element family:
Coupled Temperature-Displacement Elements
Coupled temperature-displacement elements are used in problems for which the stress
analysis depends on the temperature solution and the thermal analysis depends on the
displacement solution. An example is the heating of a deforming body whose properties are
temperature dependent by plastic dissipation or friction. The names of all coupled
temperature-displacement elements include the letter T.
Analysis Types
Coupled temperature-displacement elements are for use in fully coupled
temperature-displacement analysis (Fully Coupled Thermal-Stress Analysis).
Active Degrees of Freedom
Coupled temperature-displacement elements have both displacement and temperature degrees
of freedom. In second-order elements the temperature degrees of freedom are active at the
corner nodes (except for C3D10T elements in
Abaqus/Explicit, for which the temperature degrees of freedom are active at every node). In modified
triangle and tetrahedron elements the temperature degrees of freedom are active at every
node. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
Coupled temperature-displacement elements use either linear or parabolic interpolation
for the geometry and displacements. The temperature is always interpolated linearly except
for C3D10T elements in Abaqus/Explicit, for which parabolic interpolation is used. In second-order elements (except for
C3D10T elements in Abaqus/Explicit), curved edges should be avoided; exact linear spatial temperature variations for these
elements cannot be obtained with curved edges.
In Abaqus/Standard, for output purposes the temperature at the midside nodes of second-order elements is
determined by linear interpolation from the corner nodes.
Choosing a Coupled Temperature-Displacement Element
Coupled temperature-displacement elements are available in the following element
families:
Coupled Thermal-Electrical-Structural Elements
Coupled thermal-electrical-structural elements are used when a solution for the
displacement, electrical potential, and temperature degrees of freedom must be obtained
simultaneously. In these types of problems, coupling between the temperature and
displacement degrees of freedom arises from temperature-dependent material properties,
thermal expansion, and internal heat generation, which is a function of inelastic
deformation of the material. The coupling between the temperature and electrical degrees of
freedom arises from temperature-dependent electrical conductivity and internal heat
generation (Joule heating), which is a function of the electrical current density. The names
of the coupled thermal-electrical-structural elements begin with the letter
Q.
Analysis Types
Coupled thermal-electrical-structural elements are for use in a fully coupled
thermal-electrical-structural analysis (Fully Coupled Thermal-Electrical-Structural Analysis).
Active Degrees of Freedom
Coupled thermal-electrical-structural elements have displacement, electrical potential,
and temperature degrees of freedom. In second-order elements the electrical potential and
temperature degrees of freedom are active at the corner nodes. In modified tetrahedron
elements the electrical potential and temperature degrees of freedom are active at every
node. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
Coupled thermal-electrical-structural elements use either linear or parabolic
interpolation for the geometry and displacements. The electrical potential and temperature
are always interpolated linearly. In second-order elements curved edges should be avoided;
exact linear spatial electrical potential and temperature variations for these elements
cannot be obtained with curved edges.
For output purposes, the electrical potential and temperature at the midside nodes of
second-order elements are determined by linear interpolation from the corner nodes.
Choosing a Coupled Thermal-Electrical-Structural Element
Coupled thermal-electrical-structural elements are available only in the following
element family:
Coupled Temperature–Pore Pressure Elements
Coupled temperature–pore pressure elements are used in Abaqus/Standard for modeling fully or partially saturated fluid flow through a deforming porous medium
in which the stress, fluid pore pressure, and temperature fields are fully coupled to one
another. The names of all coupled temperature–pore pressure elements include the letters T
and P. These elements cannot be used with hydrostatic fluid elements.
Analysis Types
Coupled temperature–pore pressure elements are for use in fully coupled temperature–pore
pressure analysis (Coupled Pore Fluid Diffusion and Stress Analysis).
Active Degrees of Freedom
Coupled temperature–pore pressure elements have displacement, pore pressure, and
temperature degrees of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
These elements use either linear- or second-order (quadratic) interpolation for the
geometry and displacements. The temperature and pore pressure are always interpolated
linearly.
Choosing a Coupled Temperature–Pore Pressure Element
Coupled temperature–pore pressure elements are available in the following element family:
Diffusive (Heat Transfer) Elements
Diffusive elements are provided in Abaqus/Standard for use in heat transfer analysis (Uncoupled Heat Transfer Analysis), where they allow
for heat storage (specific heat and latent heat effects) and heat conduction. They provide
temperature output that can be used directly as input to the equivalent stress elements. The
names of all diffusive heat transfer elements begin with the letter D.
Analysis Types
The diffusive elements can be used in mass diffusion analysis (Mass Diffusion Analysis) as well as in
heat transfer analysis.
Active Degrees of Freedom
When used for heat transfer analysis, the diffusive elements have only temperature
degrees of freedom. When they are used in a mass diffusion analysis, they have normalized
concentration, instead of temperature, degrees of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
The diffusive elements use either first-order (linear) interpolation or second-order
(quadratic) interpolation in one, two, or three dimensions.
Choosing a Diffusive Element
Diffusive elements are available in the following element families:
Forced Convection Heat Transfer Elements
Forced convection heat transfer elements are provided in Abaqus/Standard to allow for heat storage (specific heat) and heat conduction, as well as the convection
of heat by a fluid flowing through the mesh (forced convection). All forced convection heat
transfer elements provide temperature output, which can be used directly as input to the
equivalent stress elements. The names of all forced convection heat transfer elements begin
with the letters DCC.
Analysis Types
The forced convection heat transfer elements can be used in heat transfer analyses (Uncoupled Heat Transfer Analysis), including
cavity radiation modeling (Cavity Radiation in Abaqus/Standard). The forced
convection heat transfer elements can be used together with the diffusive elements.
Active Degrees of Freedom
The forced convection heat transfer elements have temperature degrees of freedom. See
Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
The forced convection heat transfer elements use only first-order (linear) interpolation
in one, two, or three dimensions.
Choosing a Forced Convection Heat Transfer Element
Forced convection heat transfer elements are available only in the following element
family:
Fluid Pipe and Fluid Pipe Connector Elements
Fluid pipe elements suitable for modeling incompressible pipe flow and fluid pipe
connector elements suitable for modeling the junction between two pipes are available in Abaqus/Standard. These elements have only pore pressure degree of freedom. The names of all fluid pipe
elements begin with the letters FP. The names of all fluid
pipe connector elements begin with the letters FPC.
Analysis Types
The fluid pipe and fluid pipe connector elements can be used in the following analyses:
Active Degrees of Freedom
The fluid pipe and fluid pipe connector elements provide primarily pore pressure degree
of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Choosing a Fluid Pipe Element
The fluid pipe elements are available only in the following element family:
Choosing a Fluid Pipe Connector Element
The fluid pipe connector elements are available only in the following element family:
Thermal Fluid Pipe and Thermal Fluid Pipe Connector Elements
Thermal fluid pipe elements suitable for modeling incompressible pipe flow and temperature
fields and thermal fluid pipe connector elements suitable for modeling the junction between
two or more thermal fluid pipes are available in Abaqus/Standard. These elements have pore pressure degree of freedom to model the fluid flowing in the
pipe. In addition, temperature degrees of freedom are present at all nodes to model the
evolution of temperatures in the fluid and pipe walls. The names of all thermal fluid pipe
elements begin with the letters FP. The names of all
thermal fluid pipe connector elements begin with the letters
FPC.
Analysis Types
The thermal fluid pipe and thermal fluid pipe connector elements can be used in the
following analyses:
Active Degrees of Freedom
The thermal fluid pipe and thermal fluid pipe connector elements provide primarily pore
pressure and temperature degrees of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus. The pore pressure degree of freedom is present only on the nodes modeling the fluid
behavior, while the temperature degree of freedom is present at all nodes.
Choosing a Thermal Fluid Pipe Element
The thermal fluid pipe elements are available only in the following element family:
Choosing a Thermal Fluid Pipe Connector Element
The thermal fluid pipe connector elements are available only in the following element
family:
Coupled Thermal-Electrical Elements
Coupled thermal-electrical elements are provided in Abaqus/Standard for use in modeling heating that arises when an electrical current flows through a
conductor (Joule heating).
Analysis Types
The Joule heating effect requires full coupling of the thermal and electrical problems
(see Coupled Thermal-Electrical Analysis). The coupling
arises from two sources: temperature-dependent electrical conductivity and the heat
generated in the thermal problem by electric conduction.
These elements can also be used to perform uncoupled electric conduction analysis in all
or part of the model. In such analysis only the electric potential degree of freedom is
activated, and all heat transfer effects are ignored. This capability is available by
omitting the thermal conductivity from the material definition.
The coupled thermal-electrical elements can also be used in heat transfer analysis (Uncoupled Heat Transfer Analysis), in which case
all electric conduction effects are ignored. This feature is quite useful if a coupled
thermal-electrical analysis is followed by a pure heat conduction analysis (such as a
welding simulation followed by cool down).
The elements cannot be used in any of the stress/displacement analysis procedures.
Active Degrees of Freedom
Coupled thermal-electrical elements have both temperature and electrical potential
degrees of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
Coupled thermal-electrical elements are provided with first- or second-order
interpolation of the temperature and electrical potential.
Choosing a Coupled Thermal-Electrical Element
Coupled thermal-electrical elements are available only in the following element family:
Coupled Thermal-Electrochemical Elements
Coupled thermal-electrochemical elements are provided in Abaqus/Standard for use in modeling battery electrochemistry.
Analysis Types
The modeling of battery electrochemistry requires full coupling of the thermal,
electrical, and electrochemical problems (see Coupled Thermal-Electrochemical Analysis and Modeling Solid Electrolytes and Solid-State Batteries). The coupling
arises from the flow of electrons and ions in the solid and electrolyte phases of the
battery and the intercalation process at the solid-liquid interface.
You can use the coupled thermal-electrochemical elements only in the coupled
thermal-electrochemical analysis procedure.
Active Degrees of Freedom
Coupled thermal-electrochemical elements have temperature, electrical potential in the
solid and electrolyte phases, ion concentration, and (for solid electrolytes and
solid-state batteries) species concentration degrees of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
Coupled thermal-electrochemical elements are provided with first-order interpolation of
the five fields; namely, temperature, electrical potential in the solid and electrolyte
phases, ion concentration, and species concentration.
Choosing a Coupled Thermal-Electrochemical Element
Coupled thermal-electrochemical elements are available only in the following element
family:
Coupled Thermal-Electrochemical-Structural Elements
Coupled thermal-electrochemical-structural elements are provided in Abaqus/Standard for use in modeling battery electrochemistry.
Analysis Types
The modeling of battery electrochemistry allows for full coupling of the structural,
thermal, electrical, and electrochemical problems (see Fully Coupled Thermal-Electrochemical-Structural Analysis and Modeling Solid Electrolytes and Solid-State Batteries). The coupling
arises from the flow of electrons and ions in the solid and electrolyte phases of the
battery and the intercalation process at the solid-liquid interface. The coupling to the
mechanical degrees of freedom arises from thermal effects and particle swelling during the
intercalation/deintercalation process.
You can use the coupled thermal-electrochemical-structural elements only in the coupled
thermal-electrochemical-structural analysis procedure.
Active Degrees of Freedom
Coupled thermal-electrochemical-structural elements have displacement, temperature,
electrical potential in the solid and electrolyte phases, ion concentration, and (for
solid electrolytes and solid-state batteries) species concentration degrees of freedom.
The temperature degree of freedom is inactive if thermal conductivity is omitted from the
material definition. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
Coupled thermal-electrochemical-structural elements are provided with first-order
interpolation of the five fields; namely, displacements, temperature, electrical potential
in the solid and electrolyte phases, ion concentration, and species concentration.
Choosing a Coupled Thermal-Electrochemical-Structural Element
Coupled thermal-electrochemical-structural elements are available only in the following
element family:
Coupled Thermal-Electrochemical-Structural–Pore Pressure Elements
Coupled thermal-electrochemical-structural–pore pressure elements are provided in Abaqus/Standard for use in modeling battery electrochemistry taking into account the effects of
electrolyte fluid flow within the porous electrodes and separator.
Analysis Types
The modeling of battery electrochemistry allows for full coupling of the structural, pore
pressure, thermal, electrical, and electrochemical problems (see Fully Coupled Thermal-Electrochemical-Structural–Pore Pressure Analysis). The
electrochemical coupling arises from the interplay among the flow of electrons and ions in
the solid and electrolyte phases of the battery, respectively, and the intercalation
process at the solid-liquid interface. The thermal coupling arises from Joule and entropic
heat generation in the different components of the battery. The mechanical coupling is the
result of thermal expansion in the solid and electrolyte phases, as well as lithium
particle expansion (contraction) during the intercalation (deintercalation) process. The
pore pressure coupling is the result of the interplay between the deformation of the solid
phases and the associated pore pressure–mediated electrolyte flow in various parts of the
battery.
You can use the coupled thermal-electrochemical-structural–pore pressure elements only in
the coupled thermal-electrochemical-structural–pore pressure analysis procedure.
Active Degrees of Freedom
Coupled thermal-electrochemical-structural–pore pressure elements have the following
degrees of freedom: displacement, pore pressure, temperature, electrical potential in the
solid phase, electrical potential in the electrolyte phase, and ion concentration. The
temperature degree of freedom is inactive if thermal conductivity is omitted from the
material definition. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Interpolation
Coupled thermal-electrochemical-structural–pore pressure elements are provided with
first-order interpolation of the six fields; that is, displacement, pore pressure,
temperature, electrical potential in the solid and electrolyte phases, and ion
concentration.
Choosing a Coupled Thermal-Electrochemical-Structural–Pore Pressure Element
Coupled thermal-electrochemical-structural–pore pressure elements are available only in
the following element family:
Piezoelectric Elements
Piezoelectric elements are provided in Abaqus/Standard for problems in which a coupling between the stress and electrical potential (the
piezoelectric effect) must be modeled.
Analysis Types
Piezoelectric elements are for use in piezoelectric analysis (Piezoelectric Analysis).
Active Degrees of Freedom
The piezoelectric elements have both displacement and electric potential degrees of
freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus. The piezoelectric effect is discussed further in Piezoelectric Analysis.
Interpolation
Piezoelectric elements are available with first- or second-order interpolation of
displacement and electrical potential.
Choosing a Piezoelectric Element
Piezoelectric elements are available in the following element families:
Electromagnetic Elements
Electromagnetic elements are provided in Abaqus/Standard for problems that require the computation of the magnetic fields (such as a magnetostatic
analysis) or for problems in which a coupling between electric and magnetic fields must be
modeled (such as an eddy current analysis).
Analysis Types
Electromagnetic elements are for use in magnetostatic and eddy current analyses (Magnetostatic Analysis and Eddy Current Analysis).
Active Degrees of Freedom
Electromagnetic elements have magnetic vector potential as the degree of freedom. See
Conventions for a discussion
of the degrees of freedom in Abaqus. Magnetostatic analysis is discussed further in Magnetostatic Analysis, while the
electromagnetic coupling that occurs in an eddy current analysis is discussed further in
Eddy Current Analysis.
Interpolation
Electromagnetic elements are available with zero-order element edge–based interpolation
of the magnetic vector potential.
Choosing an Electromagnetic Element
Electromagnetic elements are available in the following element family:
Acoustic Elements
Acoustic elements are used for modeling an acoustic medium undergoing small pressure
changes. The solution in the acoustic medium is defined by a single pressure variable.
Impedance boundary conditions representing absorbing surfaces or radiation to an infinite
exterior are available on the surfaces of these acoustic elements.
Acoustic infinite elements, which improve the accuracy of analyses involving exterior
domains, and acoustic-structural interface elements, which couple an acoustic medium to a
structural model, are also provided.
Analysis Types
Acoustic elements are for use in acoustic and coupled acoustic-structural analysis (Acoustic, Shock, and Coupled Acoustic-Structural Analysis).
Active Degrees of Freedom
Acoustic elements have acoustic pressure as a degree of freedom. Coupled
acoustic-structural elements also have displacement degrees of freedom. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Choosing an Acoustic Element
Acoustic elements are available in the following element families:
The acoustic elements can be used alone but are often used with a structural model in a
coupled analysis. Acoustic Interface Elements describes interface elements
that allow this acoustic pressure field to be coupled to the displacements of the surface
of the structure. Acoustic elements can also interact with solid elements through the use
of surface-based tie constraints; see Acoustic, Shock, and Coupled Acoustic-Structural Analysis.
Poroelastic Acoustic Elements
Volumetrically coupled poroelastic acoustic elements (or simply poroelastic elements) are
used for modeling porous media undergoing small displacement and small pressure changes. The
solution is defined by displacements and pressure variables. Interface boundary conditions
connecting the poroelastic to poroelastic elements, poroelastic to elastic elements, and
poroelastic to acoustic elements are available using surface-based tie constraints.
Analysis Types
Poroelastic elements are used in acoustic and coupled acoustic-structural analysis (Acoustic, Shock, and Coupled Acoustic-Structural Analysis). They are
available only in direct steady-state dynamic linear perturbation procedures.
Active Degrees of Freedom
Poroelastic elements have translational displacements and acoustic pressure degrees of
freedom as primary variables. See Conventions for a discussion
of the degrees of freedom in Abaqus.
Choosing a Poroelastic Acoustic Element
Poroelastic elements are available only in the following element family:
Poroelastic elements can be used alone but are often used with a structural and acoustic
model in a coupled analysis. Only first-order interpolation elements for both
displacements and pressure are available.
Using the Same Mesh with Different Analysis or Element Types
You might want to use the same mesh with different analysis or element types. This might
occur, for example, if both stress and heat transfer analyses are intended for a particular
geometry or if the effect of using either reduced- or full-integration elements is being
investigated. Care should be taken when doing this since unexpected error messages may
result for one of the two element types if the mesh is distorted. For example, a stress
analysis with C3D10 elements might run
successfully, but a heat transfer analysis using the same mesh with
DC3D10 elements might terminate during the
datacheck portion of the analysis with an error message stating
that the elements are excessively distorted or have negative volumes. This apparent
inconsistency is caused by the different integration locations for the different element
types. Such problems can be avoided by ensuring that the mesh is not distorted excessively.
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