Choosing the Appropriate Element for an Analysis Type

Stress/displacement elements can be used in the following analysis types:

• static and quasi-static analysis (About Static Stress Analysis Procedures);

• implicit transient dynamic, explicit transient dynamic, modal dynamic, and steady-state dynamic analysis (About Dynamic Analysis Procedures);

• Acoustic, Shock, and Coupled Acoustic-Structural Analysis; and

• About Fracture Mechanics.

Stress/displacement elements have only displacement degrees of freedom. See Conventions for a discussion of the degrees of freedom in Abaqus.

Stress/displacement elements are available in several different element families.

Pore pressure elements can be used in the following analysis types:

• soils analysis (Coupled Pore Fluid Diffusion and Stress Analysis); and

• geostatic analysis (Geostatic Stress State).

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.

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.

Pore pressure elements are available only in the following element family:

• Solid (Continuum) Elements.

Coupled temperature-displacement elements are for use in fully coupled temperature-displacement analysis (Fully Coupled Thermal-Stress Analysis).

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. 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.

Coupled temperature-displacement elements use either linear or parabolic interpolation for the geometry and displacements. The temperature is always interpolated linearly. In second-order elements curved edges should be avoided; exact linear spatial temperature variations for these elements cannot be obtained with curved edges.

For output purposes the temperature at the midside nodes of second-order elements is determined by linear interpolation from the corner nodes.

Coupled temperature-displacement elements are available in the following element families:

• Solid (Continuum) Elements;

• Truss Elements;

• About Shell Elements;

• Gap Contact Elements; and

• Slide Line Contact Elements.

Coupled thermal-electrical-structural elements are for use in a fully coupled thermal-electrical-structural analysis (Fully Coupled Thermal-Electrical-Structural Analysis).

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.

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.

Coupled thermal-electrical-structural elements are available only in the following element family:

• Solid (Continuum) Elements.

Coupled temperature–pore pressure elements are for use in fully coupled temperature–pore pressure analysis (Coupled Pore Fluid Diffusion and Stress Analysis).

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.

These elements use either linear- or second-order (quadratic) interpolation for the geometry and displacements. The temperature and pore pressure are always interpolated linearly.

Coupled temperature–pore pressure elements are available in the following element family:

• Solid (Continuum) Elements.

The diffusive elements can be used in mass diffusion analysis (Mass Diffusion Analysis) as well as in heat transfer analysis.

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.

The diffusive elements use either first-order (linear) interpolation or second-order (quadratic) interpolation in one, two, or three dimensions.

Diffusive elements are available in the following element families:

• Solid (Continuum) Elements;

• About Shell Elements (these elements cannot be used in a mass diffusion analysis); and

• Gap Contact Elements.

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.

The forced convection heat transfer elements have temperature degrees of freedom. See Conventions for a discussion of the degrees of freedom in Abaqus.

The forced convection heat transfer elements use only first-order (linear) interpolation in one, two, or three dimensions.

Forced convection heat transfer elements are available only in the following element family:

• Solid (Continuum) Elements.

The fluid pipe and fluid pipe connector elements can be used in the following analyses:

• soils analysis (Coupled Pore Fluid Diffusion and Stress Analysis); and

• geostatic analysis (Geostatic Stress State).

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.

The fluid pipe elements are available only in the following element family:

• Fluid Pipe Elements.

The fluid pipe connector elements are available only in the following element family:

• Fluid Pipe Connector Elements.

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.

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.

Coupled thermal-electrical elements are provided with first- or second-order interpolation of the temperature and electrical potential.

Coupled thermal-electrical elements are available only in the following element family:

• Solid (Continuum) Elements.

The modeling of battery electrochemistry requires full coupling of the thermal, electrical, and electrochemical problems (see Coupled Thermal-Electrochemical Analysis). 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 interphase.

You can also use these elements to perform an electrochemical analysis where the thermal effects are ignored. This capability is available by omitting the thermal conductivity from the material definition.

You can use the coupled thermal-electrochemical elements only in the coupled thermal-electrochemical analysis procedure.

Coupled thermal-electrochemical elements have temperature, electrical potential in the solid and liquid phases, and ion concentration degrees of freedom. See Conventions for a discussion of the degrees of freedom in Abaqus.

Coupled thermal-electrochemical elements are provided with first-order interpolation of the four fields; namely, temperature, electrical potential in the solid and liquid phases, and ion concentration.

Coupled thermal-electrochemical elements are available only in the following element family:

• Solid (Continuum) Elements.

The modeling of battery electrochemistry allows for full coupling of the structural, thermal, electrical, and electrochemical problems (see Fully Coupled Thermal-Electrochemical-Structural Analysis). 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 interphase. The coupling to the mechanical degrees of freedom arises from thermal effects and particle swelling during the intercalation/deintercalation process.

You can also use these elements to perform an electrochemical analysis where the thermal effects are ignored. This capability is available by omitting the thermal conductivity from the material definition.

You can use the coupled thermal-electrochemical-structural elements only in the coupled thermal-electrochemical-structural analysis procedure.

Coupled thermal-electrochemical-structural elements have displacement, temperature, electrical potential in the solid and liquid phases, and ion 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.

Coupled thermal-electrochemical-structural elements are provided with first-order interpolation of the five fields; namely, displacements, temperature, electrical potential in the solid and liquid phases, and ion concentration.

Coupled thermal-electrochemical-structural elements are available only in the following element family:

• Solid (Continuum) Elements.

Piezoelectric elements are for use in piezoelectric analysis (Piezoelectric Analysis).

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.

Piezoelectric elements are available with first- or second-order interpolation of displacement and electrical potential.

Piezoelectric elements are available in the following element families:

• Solid (Continuum) Elements; and

• Truss Elements.

Electromagnetic elements are for use in magnetostatic and eddy current analyses (Magnetostatic Analysis and Eddy Current Analysis).

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.

Electromagnetic elements are available with zero-order element edge–based interpolation of the magnetic vector potential.

Electromagnetic elements are available in the following element family:

• Solid (Continuum) Elements.

Acoustic elements are for use in acoustic and coupled acoustic-structural analysis (Acoustic, Shock, and Coupled Acoustic-Structural Analysis).

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.

Acoustic elements are available in the following element families:

• Solid (Continuum) Elements;

• Infinite Elements; and

• Acoustic Interface Elements.

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 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.

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.

Poroelastic elements are available only in the following element family:

• Solid (Continuum) Elements.

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.