SOLID225
3D 8-Node Coupled-Field Solid
SOLID225 Element Description
SOLID225 supports the following physics combinations:
Structural-Thermal
Piezoresistive
Electrostatic-Structural
Piezoelectric
Thermal-Electric
Structural-Thermoelectric
Thermal-Piezoelectric
Structural-Diffusion
Thermal-Diffusion
Electric-Diffusion
Thermal-Electric-Diffusion
Structural-Thermal-Diffusion
Structural-Electric-Diffusion
Structural-Thermal-Electric-Diffusion
The element has eight nodes with up to six degrees of freedom per node.
Structural capabilities include elasticity, plasticity, hyperelasticity, viscoelasticity, viscoplasticity, creep, large strain, large deflection, and stress stiffening effects. It also has mixed formulation capability for simulating deformations of nearly incompressible elastoplastic materials, and fully incompressible hyperelastic materials.
For coupled-field analyses with structural degrees of freedoms (DOFs),
SOLID225 uses the full-integration 
method (also known as the selective reduced integration method). For more
information and limitations on this method, see B-Bar Method (Selective Reduced Integration). Enhanced Strain Formulation and Simplified Enhanced Strain Formulation are also supported for
structural-thermal, piezoelectric, piezoresistive, structural-diffusion,
structural-thermal-diffusion, structural-thermoelectric, structural-thermoelectric, and structural-electric-diffusion analyses. For more information on
additional DOFs, see Element Technologies.
Piezoresistive capabilities include the piezoresistive effect. Piezoelectric capabilities include direct and converse piezoelectric effects. Electrostatic-structural capabilities include electrostatic force coupling. Thermoelectric capabilities include Seebeck, Peltier, and Thomson effects, as well as Joule heating. In addition to thermal expansion, structural-thermal capabilities include the piezocaloric effect in dynamic analyses. The Coriolis effect is available for analyses with structural degrees of freedom. The thermoplastic and viscoelastic heating effects are available for analyses with structural and thermal degrees of freedom.
The diffusion expansion is available for analyses with structural and diffusion degrees of freedom. The thermo-migration effect (Soret effect) and the temperature-dependent saturated concentration effect are available for analyses with thermal and diffusion degrees of freedom. The electro-migration effect is available for analyses with electrical and diffusion degrees of freedom.
You can customize structural and thermal material behavior via the
UserMat and UserMatTh subroutines, respectively, in
coupled-field analyses with structural and thermal degrees of freedom.
See SOLID225 in the Mechanical APDL Theory Reference for more details about this element.
SOLID225 Input Data
The geometry, node locations, and the coordinate system for this element are shown in Figure 225.1: SOLID225 Geometry. The element input data includes eight nodes and structural, thermal, electrical, and diffusion material properties.
KEYOPT(1) determines the element DOF set and the corresponding force labels and reaction solution. KEYOPT(1) is set equal to the sum of the field keys shown in Table 225.1: SOLID225 Field Keys. For example, KEYOPT(1) is set to 11 for a structural-thermal analysis (structural field key + thermal field key = 1 + 10). For a structural-thermal analysis, UX, UY, and TEMP are the DOF labels and force and heat flow are the reaction solution.
Table 225.1: SOLID225 Field Keys
| Field | Field Key | DOF Label | Force Label | Reaction Solution |
|---|---|---|---|---|
| Structural | 1 | UX, UY, UZ | FX, FY, FZ | Force |
| Thermal | 10 | TEMP | HEAT | Heat Flow |
| Electric Conduction | 100 | VOLT | AMPS | Electric Current |
| Electrostatic | 1000 | VOLT | CHRG | Electric Charge |
| Diffusion | 100000 | CONC | RATE | Diffusion Flow Rate |
The coupled-field analysis KEYOPT(1) settings, DOF labels, force labels, reaction solutions, and analysis types are shown in the following table.
Table 225.2: SOLID225 Coupled-Field Analyses
| Coupled-Field Analysis | KEYOPT(1) | DOF Label | Force Label | Reaction Solution | Analysis Type |
|---|---|---|---|---|---|
| Structural-Thermal [1], [2] | 11 |
UX, UY, UZ, TEMP |
FX, FY, FZ, HEAT |
Force, Heat Flow |
Static Full Harmonic Full Transient |
| Piezoresistive | 101 |
UX, UY, UZ, VOLT |
FX, FY, FZ, AMPS |
Force, Electric Current |
Static Full Transient |
| Electrostatic-Structural | 1001 [3] |
UX, UY, UZ, VOLT |
FX, FY, FZ, CHRG |
Force, Electric Charge (negative) |
Static Full Transient Linear Perturbation Static Linear Perturbation Harmonic Linear Perturbation Modal |
| Piezoelectric (Charge-Based) | 1001 [3] |
UX, UY, UZ, VOLT |
FX, FY, FZ, CHRG |
Force, Electric Charge (negative) |
Static Modal Linear Perturbation Modal Full, Linear Perturbation, or Mode Superposition Harmonic Full or Mode Superposition Transient |
| Piezoelectric (Current-Based) | 101 |
UX, UY, UZ, VOLT |
FX, FY, FZ, AMPS |
Force, Electric Current |
Full Harmonic Full Transient |
| Thermal-Electric | 110 |
TEMP, VOLT |
HEAT, AMPS |
Heat Flow, Electric Current |
Static Full Transient |
| Structural-Thermoelectric [1] | 111 |
UX, UY, UZ, TEMP, VOLT |
FX, FY, FZ, HEAT, AMPS |
Force, Heat Flow, Electric Current |
Static Full Transient |
| Thermal-Piezoelectric [1], [2] | 1011 |
UX, UY, UZ, TEMP, VOLT |
FX, FY, FZ, HEAT, CHRG |
Force, Heat Flow, Electric Charge (negative) |
Static Full Harmonic Full Transient |
| Structural-Diffusion [1] | 100001 |
UX, UY, UZ, CONC |
FX, FY, FZ, RATE |
Force, Diffusion Flow Rate |
Static Full Transient |
| Thermal-Diffusion [1] | 100010 |
TEMP, CONC |
HEAT, RATE |
Heat Flow, Diffusion Flow Rate |
Static Full Transient |
| Electric-Diffusion [1] | 100100 |
VOLT, CONC |
AMP, RATE |
Electric Current, Diffusion Flow Rate |
Static Full Transient |
| Thermal-Electric Diffusion [1] | 100110 |
TEMP, VOLT, CONC |
HEAT, AMP, RATE |
Heat Flow, Electric Current, Diffusion Flow Rate |
Static Full Transient |
| Structural-Thermal-Diffusion [1] | 100011 |
UX, UY, UZ, TEMP, CONC |
FX, FY, FZ, HEAT, RATE |
Force, Heat Flow, Diffusion Flow Rate |
Static Full Transient |
| Structural-Electric-Diffusion [1] | 100101 |
UX, UY, UZ, VOLT, CONC |
FX, FY, FZ, AMPS, RATE |
Force, Electric Current, Diffusion Flow Rate |
Static Full Transient |
| Structural-Thermal-Electric-Diffusion [1] | 100111 |
UX, UY, UZ, TEMP, VOLT, CONC |
FX, FY, FZ, HEAT, AMPS, RATE |
Force, Heat Flow, Electric Current, Diffusion Flow Rate |
Static Full Transient |
For static and full transient analyses, KEYOPT(2) can specify a strong (matrix) or weak (load vector) structural-thermal, structural-diffusion, thermal-diffusion, and electric-diffusion coupling.
For harmonic analyses, only strong coupling (KEYOPT(2) = 0) applies.
The electrostatic-structural analysis available with KEYOPT(1) = 1001 defaults to electrostatic force coupling. To turn off the electrostatic force coupling, you can set KEYOPT(4) = 2 for elastic air or KEYOPT(4) = 4 for solid dielectrics, respectively. Alternatively, to do an uncoupled structural-electrostatic analysis, you can specify a negligible piezoelectric coefficient using TBDATA with TB,PIEZ.
As shown in the following tables, material property requirements consist of those required for the individual fields (structural, thermal, electric conduction, electrostatic, or diffusion) and those required for field coupling. Individual material properties are defined via the MP and MPDATA commands. Nonlinear and multiphysics material models are defined via the TB command.
Table 225.3: Structural Material Properties
| Field | Field Key | Material Properties and Material Models |
|---|---|---|
| Structural | 1 |
EX, EY, EZ, PRXY, PRYZ, PRXZ (or NUXY, NUYZ, NUXZ), GXY, GYZ, GXZ, DENS, ALPD, BETD, DMPR, DMPS ALPX, ALPY, ALPZ (or CTEX, CTEY, CTEZ, or THSX, THSY, THSZ), REFT --- Anisotropic hyperelasticity, Anisotropic elasticity, Bergstrom-Boyce, Bilinear isotropic hardening, Bilinear kinematic hardening, Cast iron, Chaboche nonlinear kinematic hardening, Creep, Elasticity, Extended Drucker-Prager, Gurson pressure-dependent plasticity, Hill anisotropy, Hyperelasticity, Mullins effect, Voce isotropic hardening law, Plasticity, Prony series constants for viscoelastic materials, Rate-dependent plasticity (viscoplasticity), Rate-independent plasticity, Material-dependent alpha and beta damping (Rayleigh damping), Material-dependent structural damping, Shift function for viscoelastic materials, Shape memory alloy, State variables (user-defined), User-defined (structural and thermal), Uniaxial stress-strain relation |
Table 225.4: SOLID225 Material Properties and Material Models
| Coupled-Field Analysis | KEYOPT(1) | Material Properties and Material Models | |
|---|---|---|---|
| Structural-Thermal | 11 | Structural | See Table 225.3: Structural Material Properties |
| Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF, State variables (user-defined), User-defined (structural and thermal) | ||
| Coupling |
ALPX, ALPY, ALPZ, REFT, QRATE | ||
| Piezoresistive [1] | 101 | Structural | See Table 225.3: Structural Material Properties |
| Electric |
RSVX, RSVY, RSVZ, PERX, PERY, PERZ | ||
| Coupling | |||
| Electrostatic-structural | 1001 | Structural | See Table 225.3: Structural Material Properties |
| Electric |
PERX, PERY, PERZ, LSST (and/or RSVX, RSVY, RSVZ) --- Anisotropic electric permittivity --- | ||
| Piezoelectric |
1001 (Charge-Based) 101 (Current-Based) | Structural |
See Table 225.3: Structural Material Properties [2] --- --- |
| Electric |
PERX, PERY, PERZ, LSST (and/or RSVX, RSVY, RSVZ) --- Anisotropic electric permittivity --- | ||
| Coupling | |||
| Thermal-Electric [1] | 110 | Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF |
| Electric |
RSVX, RSVY, RSVZ, PERX, PERY, PERZ | ||
| Coupling |
SBKX, SBKY, SBKZ | ||
| Structural-Thermoelectric | 111 | Structural | See Table 225.3: Structural Material Properties |
| Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF | ||
| Electric |
RSVX, RSVY, RSVZ, PERX, PERY, PERZ | ||
| Coupling |
ALPX, ALPY, ALPZ, REFT, QRATE --- SBKX, SBKY, SBKZ --- | ||
| Thermal-Piezoelectric | 1011 | Structural | See Table 225.3: Structural Material Properties [2] |
| Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF | ||
| Electric |
PERX, PERY, PERZ, LSST (and/or RSVX, RSVY, RSVZ) --- | ||
| Coupling |
ALPX, ALPY, ALPZ, REFT --- | ||
| Structural-Diffusion [1] | 100001 | Structural | See Table 225.3: Structural Material Properties |
| Diffusion |
DXX, DYY, DZZ, CSAT | ||
| Coupling |
BETX, BETY, BETZ, CREF | ||
| Thermal-Diffusion [1] | 100010 | Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF |
| Diffusion |
DXX, DYY, DZZ, CSAT | ||
| Coupling |
Temperature-dependent CSAT --- | ||
| Electric-Diffusion [1] | 100100 | Electric |
RSVX, RSVY, RSVZ, PERX, PERY, PERZ |
| Diffusion |
DXX, DYY, DZZ, CSAT | ||
| Coupling | |||
| Thermal-Electric Diffusion [1] | 100110 | Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF |
| Electric |
RSVX, RSVY, RSVZ, PERX, PERY, PERZ | ||
| Diffusion |
DXX, DYY, DZZ, CSAT | ||
| Coupling |
SBKX, SBKY, SBKZ --- Temperature-dependent CSAT --- | ||
| Structural-Thermal-Diffusion [1] | 100011 | Structural | See Table 225.3: Structural Material Properties |
| Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF | ||
| Diffusion |
DXX, DYY, DZZ, CSAT | ||
| Coupling |
ALPX, ALPY, ALPZ, REFT, QRATE --- BETX, BETY, BETZ, CREF --- Temperature-dependent CSAT --- | ||
| Structural-Electric-Diffusion [1] | 100101 | Structural | See Table 225.3: Structural Material Properties |
| Electric |
RSVX, RSVY, RSVZ, PERX, PERY, PERZ | ||
| Diffusion |
DXX, DYY, DZZ, CSAT | ||
| Coupling |
BETX, BETY, BETZ, CREF --- | ||
| Structural-Thermal-Electric-Diffusion [1] | 100111 | Structural | See Table 225.3: Structural Material Properties |
| Thermal |
KXX, KYY, KZZ, DENS, C, ENTH, HF | ||
| Electric |
RSVX, RSVY, RSVZ, PERX, PERY, PERZ | ||
| Diffusion |
DXX, DYY, DZZ, CSAT | ||
| Coupling |
ALPX, ALPY, ALPZ, REFT, QRATE --- BETX, BETY, BETZ, CREF --- SBKX, SBKY, SBKZ --- Temperature-dependent CSAT --- | ||
For this analysis type, some of the material properties can be defined as a function of primary variables by using tabular input on the MP command. For more information, see Defining Linear Material Properties Using Tabular Input in the Material Reference.
For piezoelectric and thermal-piezoelectric analyses (KEYOPT(1) = 101, 1001, or 1011 with TB,PIEZ), only elastic material properties and material models are valid.
Various combinations of nodal loading are available for this element (depending upon the KEYOPT(1) value). Nodal loads are defined with the D and the F commands.
Element loads are described in Element Loading. Loads may be input on the element faces indicated by the circled numbers in Figure 225.1: SOLID225 Geometry using the SF and SFE commands. Positive pressures act into the element. Body loads may be input at the element's nodes or as a single element value using the BF and BFE commands.
SOLID225 surface and body loads are given in the following table. CHRGS and CHRGD are interpreted as negative surface charge density and negative volume charge density, respectively.
Most surface and body loads can be defined as a function of primary variables by using tabular input. For more information, see Applying Loads Using Tabular Input in the Basic Analysis Guide and the individual surface or body load command description in the Command Reference.
Table 225.5: SOLID225 Surface and Body Loads
| Coupled-Field Analysis | KEYOPT(1) | Load Type | Load | Command Label | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Structural-Thermal | 11 | Surface |
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| Piezoresistive and Piezoelectric (Current-Based) | 101 | Surface |
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| Electrostatic-Structural and Piezoelectric (Charge-Based) | 1001 | Surface |
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| Thermal-Electric | 110 | Surface |
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| Structural-Thermoelectric | 111 | Surface |
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| Thermal-Piezoelectric | 1011 | Surface |
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| Structural-Diffusion | 100001 | Surface |
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| Thermal-Diffusion | 100010 | Surface |
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| Electric-Diffusion | 100100 | Surface |
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| Thermal-Electric-Diffusion | 100110 | Surface |
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| Structural-Thermal-Diffusion | 100011 | Surface |
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| Structural-Electric-Diffusion | 100101 | Surface |
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| Structural-Thermal-Electric-Diffusion | 100111 | Surface |
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Automatic element technology selections are given in the following table (for more information, see Automatic Selection of Element Technologies and Formulations).
Table 225.6: Automatic Element Technology Selection
| Coupled-Field Analysis | ETCONTROL Command Suggestions/Resettings |
|---|---|
| All analyses with structural and thermal fields | KEYOPT(2) = 1 for elastoplastic or hyperelastic materials |
| Analyses with a structural field that support the enhanced strain (KEYOPT(6) = 2) or simplified enhanced strain (KEYOPT(6) = 3) formulations | KEYOPT(6) = 3 for linear materials with Poisson’s ratio ν ≤ 0.49 only KEYOPT(6) = 2 for linear materials with Poisson’s ratio ν > 0.49 or anisotropic materials onlyKEYOPT(6) = 2 for elastoplastic materials[a] KEYOPT(6) = 0 for hyperelastic materials only |
[a] Hyperelastic materials may be present.
A summary of the element input is given in "SOLID225 Input Summary". A general description of element input is given in Element Input.
SOLID225 Input Summary
- Nodes
I, J, K, L, M, N, O, P
- Degrees of Freedom
Set by KEYOPT(1). See Table 225.2: SOLID225 Coupled-Field Analyses.
- Real Constants
none
- Material Properties
See Table 225.4: SOLID225 Material Properties and Material Models.
- Surface Loads
- Body Loads
- Special Features
Birth and death Coriolis effect Element technology autoselect Large deflection Large strain Linear perturbation (see Note below) Nonlinear stabilization Stress stiffening Note: Linear perturbation is available for the following coupled analyses: electrostatic-structural and piezoelectric analyses (KEYOPT(1) = 1001).
- KEYOPT(1)
Element degrees of freedom. See Table 225.2: SOLID225 Coupled-Field Analyses.
- KEYOPT(2)
Coupling method between the DOFs for the following types of coupling: structural-thermal, structural-diffusion, thermal-diffusion, thermal-electric, and electric-diffusion:
Note:
In addition to unsymmetric constitutive equations, temperature-dependent thermal conductivity, electrical resistivity, and diffusivity produce unsymmetric matrices. Effects associated with the temperature-dependent material properties are not taken into account with the weak coupling option (KEYOPT(2) = 1).
The weak coupling option (KEYOPT(2) = 1) can be used in a coupled electrostatic-structural analysis (KEYOPT(1) = 1001) to produce legacy element behavior. In this case, the reaction solution for the VOLT degree of freedom is positive charge (CHRG), and the analysis types are limited to static and full transient analyses. Linear perturbation analyses are not supported.
- KEYOPT(4)
Electrostatic force coupling in electrostatic-structural analysis (KEYOPT(1) = 1001):
- 0 --
Applied to every element node. Used to model electrostatic or electromagnetic force coupling in solids.
- 1 --
Applied to the air-structure interface or to element nodes that have constrained structural degrees of freedom. Produces a symmetric electrostatic force coupling matrix by ignoring some terms associated with the nodes interior to the air domain. Recommended for models with a single layer of elastic air elements without midside nodes.
- 2 --
Not applied. Recommended for elastic air elements not directly attached to the air-structure interface to make the solution more efficient.
- 3 --
Applied to the air-structure interface or to element nodes that have constrained structural degrees of freedom. Compared to KEYOPT(4) = 1, all terms of the electrostatic force coupling matrix are retained, which produces an unsymmetric matrix. Recommended for models with multiple layers of elastic air elements.
- 4 --
Not applied. Can be used to turn off the default electrostatic or electromagnetic force coupling in solids. Compared to KEYOPT(4) = 2, elements with KEYOPT(4) = 4 can be subject to electrostatic or electromagnetic force coupling when connected to an elastic air element.
Note: KEYOPT(4) = 1, 2, and 3 are used to identify elastic air elements during the automatic detection of the air-structure interface. The electrostatic or electromagnetic force coupling:
Will not be applied to the element nodes connected to another elastic air element.
Will be applied to the element nodes connected to a structure, that is, any element with structural degrees of freedom except for the elastic air elements.
For more information, see Electrostatic-Structural Analysis in the Coupled-Field Analysis Guide and Electroelasticity in the Mechanical APDL Theory Reference.
- KEYOPT(6)
Element technology:
- 0 --
Full integration with
method (default).- 2 --
Enhanced strain formulation. (Available for the coupled analyses listed in the note.)
- 3 --
Simplified enhanced strain formulation. (Available for the coupled analyses listed in the note.)
Note: The enhanced strain and simplified enhanced strain formulations are available for the following coupled analyses:
Structural-thermal (KEYOPT(1)=11) with thermoelastic damping turned off (KEYOPT(9)=1) Piezoelectric (KEYOPT(1) = 1001) Piezoresistive (KEYOPT(1)=101) Structural-diffusion (KEYOPT(1) = 100001) Structural-thermal-diffusion (KEYOPT(1) = 100011) Structural-thermoelectric (KEYOPT(1) = 111) Structural-electric-diffusion (KEYOPT(1) = 100101) - KEYOPT(9)
Thermoelastic damping (piezocaloric effect) in coupled-field analyses having structural and thermal degrees of freedom.
- 0 --
Active. Evaluated at the reference temperature. Applicable to harmonic and transient analyses.
- 1 --
Suppressed (required for frictional heating analyses).
- 2 --
Active. Evaluated at the actual temperature. Applicable to a transient analysis.
- KEYOPT(10)
Damping matrix in coupled-field analyses having the diffusion DOF (CONC).
- 0 --
Consistent
- 1 --
Diagonalized
- KEYOPT(11)
Element formulation in coupled-field analyses with structural DOFs:
- 0 --
Pure displacement formulation (default)
- 1 --
Mixed u-P formulation
- KEYOPT(15)
Perfectly matched layers (PML) absorbing condition in a harmonic piezoelectric analysis (KEYOPT(1) = 1001):
- 0 --
Do not include the PML absorbing condition (default)
- 1 --
Include the PML absorbing condition
SOLID225 Output Data
The solution output associated with the element is in two forms:
Nodal degrees of freedom included in the overall nodal solution
Additional element output as shown in Table 225.7: SOLID225 Element Output Definitions.
The element output directions are parallel to the element coordinate system. A general description of solution output is given in Solution Output. See the Basic Analysis Guide for ways to view results.
The Element Output Definitions table uses the following notation:
A colon (:) in the Name column indicates that the item can be accessed by the Component Name method (ETABLE, ESOL). The O column indicates the availability of the items in the file jobname.out. The R column indicates the availability of the items in the results file.
In either the O or R columns, “Y” indicates that the item is always available, a letter or number refers to a table footnote that describes when the item is conditionally available, and “-” indicates that the item is not available.
Table 225.7: SOLID225 Element Output Definitions
| Name | Definition | O | R |
|---|---|---|---|
| ALL ANALYSES | |||
| EL | Element Number | - | Y |
| NODES | Nodes - I, J, K, L, M, N, O, P | - | Y |
| MAT | Material number | - | Y |
| VOLU: | Volume | - | Y |
| XC, YC, ZC | Location where results are reported | - | 2 |
| ALL ANALYSES WITH A STRUCTURAL FIELD | |||
| S:X, Y, Z, XY, YZ, XZ | Stresses (SZ = 0.0 for plane stress elements) | - | 1 |
| S:1, 2, 3 | Principal stresses | - | 1 |
| S:EQV | Equivalent stress | - | 1 |
| EPEL:X, Y, Z, XY, YZ, XZ | Elastic strains | - | 1 |
| EPEL:EQV | Equivalent elastic strain [3] | - | 1 |
| EPTH:X, Y, Z, XY, YZ, XZ | Thermal strains | - | 1 |
| EPTH:EQV | Equivalent thermal strain [3] | - | 1 |
| EPPL:X, Y, Z, XY, YZ, XZ | Plastic strains | - | 1 |
| EPPL:EQV | Equivalent plastic strain [3] | - | 1 |
| EPCR:X, Y, Z, XY, YZ, XZ | Creep strains | - | 1 |
| EPCR:EQV | Equivalent creep strain [3] | - | 1 |
| EPTO:X, Y, Z, XY, YZ, XZ | Total mechanical strains (EPEL + EPPL + EPCR) | Y | - |
| EPTO:EQV | Total equivalent mechanical strain (EPEL + EPPL + EPCR) | - | - |
| EPTT:X, Y, Z, XY, YZ, XZ | Total mechanical, thermal, and diffusion strains (EPEL + EPPL + EPCR + EPTH + EPDI) | - | - |
| EPTT:EQV | Total equivalent mechanical strain (EPEL + EPPL + EPCR + EPTH + EPDI) | - | - |
| NL:SEPL | Plastic yield stress [10] | - | Y |
| NL:EPEQ | Accumulated equivalent plastic strain [10] | - | Y |
| NL:CREQ | Accumulated equivalent creep strain [10] | - | Y |
| NL:SRAT | Plastic yielding (1 = actively yielding, 0 = not yielding) [10] | - | Y |
| NL:HPRES | Hydrostatic pressure [10] | - | Y |
| SENE: | Elastic strain energy | - | Y |
| ADDITIONAL OUTPUT FOR STRUCTURAL-THERMAL ANALYSES (KEYOPT(1) = 11) [11] | |||
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| UE | Elastic strain energy [7] | - | 1 |
| UT | Total strain energy [8] | - | 1 |
| PHEAT | Plastic heat generation rate per unit volume | - | 1 |
| VHEAT | Viscoelastic heat generation rate per unit volume | - | 1 |
| ADDITIONAL OUTPUT FOR PIEZORESISTIVE ANALYSES (KEYOPT(1) = 101) [11] | |||
| TEMP | Input temperatures | - | Y |
| EF:X, Y, Z, SUM | Electric field components (X, Y, Z) and vector magnitude | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components (X, Y, Z) and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Current density components (in the global Cartesian coordinate system) and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5] | - | 1 |
| ADDITIONAL OUTPUT FOR ELECTROSTATIC-STRUCTURAL ANALYSES (KEYOPT(1) = 1001) [11] | |||
| TEMP | Input temperatures | - | Y |
| EF:X, Y, Z, SUM | Electric field components (X, Y, Z) and vector magnitude | - | 1 |
| D:X, Y, Z, SUM | Electric flux density components (X, Y, Z) and vector magnitude | - | 1 |
| FMAG:X, Y, Z, SUM | Electrostatic force components (X, Y, Z) and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Element current density components (X, Y, Z) in the global Cartesian coordinate system and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| UE, UM, UD | Elastic, mutual, and dielectric energies [7] | - | 1 |
| SENE | Sum of elastic and dielectric energies (UE+UD) [7] | - | 1 |
| DENE | Damping energy [7] | - | 1 |
| KENE | Kinetic energy [7] | - | 1 |
| ADDITIONAL OUTPUT FOR PIEZOELECTRIC ANALYSES (KEYOPT(1) = 1001 and KEYOPT(1) = 101) [11] | |||
| TEMP | Input temperatures | - | Y |
| EF:X, Y, Z, SUM | Electric field components (X, Y, Z) and vector magnitude | - | 1 |
| D:X, Y, Z, SUM | Electric flux density components (X, Y, Z) and vector magnitude; available only for charge-based analysis (KEYOPT(1) = 1001) | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components (X, Y, Z) and vector magnitude; available only for current-based analysis (KEYOPT(1) = 101) | - | 1 |
| JS:X, Y, Z, SUM | Element current density components (X, Y, Z) in the global Cartesian coordinate system and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| UE, UM, UD | Elastic, mutual, and dielectric energies [7] | - | 1 |
| UT | Total strain energy [8] | - | 1 |
| SENE | Sum of elastic and dielectric energies (UE+UD) [7] | - | 1 |
| DENE | Damping energy [7] | - | 1 |
| KENE | Kinetic energy [7] | - | 1 |
| P:X, Y, Z, SUM | Element Poynting vector components (X, Y, Z) and vector magnitude [7] | - | 1 |
| THERMAL-ELECTRIC ANALYSES (KEYOPT(1) = 110) | |||
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| EF:X, Y, Z, SUM | Electric field components and vector magnitude | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Current density components (in the global Cartesian coordinate system) and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| ADDITIONAL OUTPUT FOR STRUCTURAL-THERMOELECTRIC ANALYSES (KEYOPT(1) = 111) [11] | |||
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| EF:X, Y, Z, SUM | Electric field components and vector magnitude | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Current density components components (in the global Cartesian coordinate system) and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| UE | Elastic strain energy | - | 1 |
| UT | Total strain energy [8] | - | 1 |
| PHEAT | Plastic heat generation rate per unit volume | - | 1 |
| VHEAT | Viscoelastic heat generation rate per unit volume | - | 1 |
| ADDITIONAL OUTPUT FOR THERMAL-PIEZOELECTRIC ANALYSES (KEYOPT(1) = 1011) [11] | |||
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| EF:X, Y, Z, SUM | Electric field components and vector magnitude | - | 1 |
| D:X, Y, Z, SUM | Electric flux density components and vector magnitude | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| UE, UM, UD | Elastic, mutual, and dielectric energies [7] | - | 1 |
| UT | Total strain energy [8] | - | 1 |
| PHEAT | Plastic heat generation rate per unit volume | - | 1 |
| VHEAT | Viscoelastic heat generation rate per unit volume | - | 1 |
| ADDITIONAL OUTPUT FOR STRUCTURAL-DIFFUSION ANALYSES (KEYOPT(1)=100001) [11] | |||
| TEMP | Input temperatures | - | Y |
| EPDI:X, Y, Z, XY, YZ, XZ | Diffusion strains | - | 1 |
| CG:X, Y, Z, SUM | Concentration gradient components and vector magnitude | - | 1 |
| DF:X, Y, Z, SUM | Diffusion flux components and vector magnitude | - | 1 |
| CONC | Element concentration [9] | - | 1 |
| DFC:X,Y,Z,SUM | Pure diffusion flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFS:X,Y,Z,SUM | Stress migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| THERMAL-DIFFUSION ANALYSES (KEYOPT(1) = 100010) | |||
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| CG:X, Y, Z, SUM | Concentration gradient components and vector magnitude | - | 1 |
| DF:X, Y, Z, SUM | Diffusion flux components and vector magnitude | - | 1 |
| CONC | Element concentration [9] | - | 1 |
| DFC:X,Y,Z,SUM | Pure diffusion flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFT:X,Y,Z,SUM | Thermal migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| ELECTRIC-DIFFUSION ANALYSES (KEYOPT(1) = 100100) | |||
| TEMP | Input temperatures | - | Y |
| EF:X, Y, Z, SUM | Electric field components and vector magnitude | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Current density components (in the global Cartesian coordinate system) and vector magnitude [4] | - | 1 |
| CG:X, Y, Z, SUM | Concentration gradient components and vector magnitude | - | 1 |
| DF:X, Y, Z, SUM | Diffusion flux components and vector magnitude | - | 1 |
| CONC | Element concentration [9] | - | 1 |
| DFC:X,Y,Z,SUM | Pure diffusion flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFE:X,Y,Z,SUM | Electric migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| THERMAL-ELECTRIC-DIFFUSION ANALYSES (KEYOPT(1) = 100110) | |||
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| EF:X, Y, Z, SUM | Electric field components and vector magnitude | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Current density components (in the global Cartesian coordinate system) and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| CG:X, Y, Z, SUM | Concentration gradient components and vector magnitude | - | 1 |
| DF:X, Y, Z, SUM | Diffusion flux components and vector magnitude | - | 1 |
| CONC | Element concentration [9] | - | 1 |
| DFC:X,Y,Z,SUM | Pure diffusion flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFT:X,Y,Z,SUM | Thermal migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFE:X,Y,Z,SUM | Electric migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| ADDITIONAL OUTPUT FOR STRUCTURAL-ELECTRIC-DIFFUSION ANALYSES (KEYOPT(1) = 100101) [11] | |||
| TEMP | Input temperatures | - | Y |
| EPDI:X, Y, Z, XY, YZ, XZ | Diffusion strains | - | 1 |
| EF:X, Y, Z, SUM | Electric field components and vector magnitude | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Current density components (in the global Cartesian coordinate system) and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| CG:X, Y, Z, SUM | Concentration gradient components and vector magnitude | - | 1 |
| DF:X, Y, Z, SUM | Diffusion flux components and vector magnitude | - | 1 |
| CONC | Element concentration [9] | - | 1 |
| DFC:X,Y,Z,SUM | Pure diffusion flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFS:X,Y,Z,SUM | Stress migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFE:X,Y,Z,SUM | Electric migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| ADDITIONAL OUTPUT FOR STRUCTURAL-THERMAL-DIFFUSION ANALYSES (KEYOPT(1) = 100011) [11] | |||
| EPDI:X, Y, Z, XY, YZ, XZ | Diffusion strains | - | 1 |
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| CG:X, Y, Z, SUM | Concentration gradient components and vector magnitude | - | 1 |
| DF:X, Y, Z, SUM | Diffusion flux components and vector magnitude | - | 1 |
| CONC | Element concentration [9] | - | 1 |
| DFC:X,Y,Z,SUM | Pure diffusion flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFS:X,Y,Z,SUM | Stress migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFT:X,Y,Z,SUM | Thermal migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| PHEAT | Plastic heat generation rate per unit volume | - | 1 |
| VHEAT | Viscoelastic heat generation rate per unit volume | - | 1 |
| ADDITIONAL OUTPUT FOR STRUCTURAL-THERMAL-ELECTRIC-DIFFUSION ANALYSES (KEYOPT(1) = 100111) [11] | |||
| EPDI:X, Y, Z, XY, YZ, XZ | Diffusion strains | - | 1 |
| TG:X, Y, Z, SUM | Thermal gradient components and vector magnitude | - | 1 |
| TF:X, Y, Z, SUM | Thermal flux components and vector magnitude | - | 1 |
| EF:X, Y, Z, SUM | Electric field components and vector magnitude | - | 1 |
| JC:X, Y, Z, SUM | Conduction current density components and vector magnitude | - | 1 |
| JS:X, Y, Z, SUM | Current density components (in the global Cartesian coordinate system) and vector magnitude [4] | - | 1 |
| JHEAT | Joule heat generation per unit volume [5], [6] | - | 1 |
| CG:X, Y, Z, SUM | Concentration gradient components and vector magnitude | - | 1 |
| DF:X, Y, Z, SUM | Diffusion flux components and vector magnitude | - | 1 |
| CONC | Element concentration [9] | - | 1 |
| DFC:X,Y,Z,SUM | Pure diffusion flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFS:X,Y,Z,SUM | Stress migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFT:X,Y,Z,SUM | Thermal migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| DFE:X,Y,Z,SUM | Electric migration flux components (X,Y,Z) and vector magnitude | - | 1 |
| PHEAT | Plastic heat generation rate per unit volume | - | 1 |
| VHEAT | Viscoelastic heat generation rate per unit volume | - | 1 |
Solution values are output only if calculated (based on input values).
Available only at centroid as a *GET item.
The equivalent strains use an effective Poisson's ratio: for elastic and thermal this value is set by the user (MP,PRXY); for plastic and creep this value is set at 0.5.
JS represents the sum of element conduction and displacement current densities.
Calculated Joule heat generation rate per unit volume (JHEAT) may be made available for a subsequent thermal analysis with companion thermal elements. For piezoelectric and electrostatic-structural analyses, the heat generation rate output as JHEAT is produced by both the supported structural and electrical losses.
For a time-harmonic analysis, Joule losses (JHEAT) are time-averaged. These values are stored in both the real and imaginary data sets. For more information, see Quasistatic Electric Analysis in the Mechanical APDL Theory Reference.
For time-harmonic and modal analyses the following values are time-averaged: elastic (UE), mutual (UM), and dielectric (UD) energies, the sum of elastic and dielectric energies (SENE), damping energy (DENE), kinetic energy (KENE), and the Poynting vector (P). The real part of the UE, UM, UD, and SENE records represents the average energy, while the imaginary part represents the average energy loss. The real part of the Poynting vector represents the average power flow. For more information, see Piezoelectrics and Electroelasticity in the Mechanical APDL Theory Reference.
For a time-harmonic analysis, total strain (UT) energy is time-averaged. The real part represents the average energy, while the imaginary part represents the average energy loss. For more information, see Thermoelasticity in the Mechanical APDL Theory Reference.
With the normalized concentration approach, CONC is the actual concentration obtained by multiplying the saturated concentration (MP,CSAT) and the normalized concentration evaluated at the element centroid. For more information, see Normalized Concentration Approach in the Theory Reference.
Nonlinear solution, output only if the element has a nonlinear material, or if large-deflection effects are enabled (NLGEOM,ON).
Output listed for this coupled analysis is in addition to the structural field output at the beginning of this table.
Table 225.7: SOLID225 Element Output Definitions lists output available through the ETABLE command using the Sequence Number method. See The General Postprocessor (POST1) of the Basic Analysis Guide and The Item and Sequence Number Table of this reference for more information. The following notation is used in Table 225.8: SOLID225 Item and Sequence Numbers:
- Name
output quantity as defined in the Table 225.7: SOLID225 Element Output Definitions
- Item
predetermined Item label for ETABLE command
- E
sequence number for single-valued or constant element data
Table 225.8: SOLID225 Item and Sequence Numbers
| Output Quantity Name | ETABLE Command Input | |||
|---|---|---|---|---|
| Item | E | |||
| Analyses that include DIFFUSION (KEYOPT(1) = 100001, 100010, 100100, 100110, 100011, 100101, and 100111) | ||||
| CONC | SMISC | 1 | ||
| DFCX | SMISC | 2 | ||
| DFCY | SMISC | 3 | ||
| DFCZ | SMISC | 4 | ||
| DFCSUM | SMISC | 5 | ||
| DFSX | SMISC | 6 | ||
| DFSY | SMISC | 7 | ||
| DFSZ | SMISC | 8 | ||
| DFSSUM | SMISC | 9 | ||
| DFTX | SMISC | 10 | ||
| DFTY | SMISC | 11 | ||
| DFTZ | SMISC | 12 | ||
| DFTSUM | SMISC | 13 | ||
| DFEX | SMISC | 14 | ||
| DFEY | SMISC | 15 | ||
| DFEZ | SMISC | 16 | ||
| DFESUM | SMISC | 17 | ||
| STRUCTURAL-THERMAL ANALYSES (KEYOPT(1) = 11) | ||||
| UE | NMISC | 1 | ||
| UT | NMISC | 4 | ||
| PHEAT | NMISC | 5 | ||
| VHEAT | NMISC | 6 | ||
| ELECTROSTATIC-STRUCTURAL ANALYSES (KEYOPT(1) = 1001) | ||||
| UE | NMISC | 1 | ||
| UD | NMISC | 2 | ||
| UM | NMISC | 3 | ||
| PIEZOELECTRIC ANALYSES: (KEYOPT(1) = 1001 and 101) | ||||
| UE | NMISC | 1 | ||
| UD | NMISC | 2 | ||
| UM | NMISC | 3 | ||
| UT | NMISC | 4 | ||
| PX | NMISC | 5 | ||
| PY | NMISC | 6 | ||
| PZ | NMISC | 7 | ||
| PSUM | NMISC | 8 | ||
| STRUCTURAL-THERMOELECTRIC ANALYSES (KEYOPT(1) = 111) | ||||
| UE | NMISC | 1 | ||
| UT | NMISC | 4 | ||
| PHEAT | NMISC | 5 | ||
| VHEAT | NMISC | 6 | ||
| THERMAL-PIEZOELECTRIC ANALYSES (KEYOPT(1) = 1011) | ||||
| UE | NMISC | 1 | ||
| UD | NMISC | 2 | ||
| UM | NMISC | 3 | ||
| UT | NMISC | 4 | ||
| PHEAT | NMISC | 5 | ||
| VHEAT | NMISC | 6 | ||
| ||||
| PHEAT | NMISC | 5 | ||
| VHEAT | NMISC | 6 | ||
SOLID225 Assumptions and Restrictions
In a piezoelectric or electrostatic-structural analysis, electric charge loading is interpreted as negative electric charge or negative charge density.
Optimized nonlinear solution defaults are applied in coupled-field analyses with structural degrees of freedom using this element.
This element may not be compatible with other elements with the VOLT degree of freedom. To be compatible, the elements must have the same reaction solution for the VOLT DOF. Elements that have an electric charge reaction solution must all have the same electric charge reaction sign. For more information, see Element Compatibility in the Low-Frequency Electromagnetic Analysis Guide.
When using mixed formulation (KEYOPT(11) = 1), use the sparse solver (default).
Stress stiffening is always included in geometrically nonlinear (NLGEOM,ON) coupled-field analyses with structural degrees of freedom. Prestress effects can be activated via the PSTRES command.
Graphical Solution Tracking (/GST) is not supported for the analyses with CONC DOFs (KEYOPT(1) = 100001, 100010, 100011, 100100, 100101, 100110, and 100111).
Reaction forces are not available for electrostatic-structural (KEYOPT(1) = 1001) analyses with the elastic air option (KEYOPT(4) = 1).
The stress-migration effect (specified using TB,MIGR) is not supported in an analysis with structural and diffusion degrees of freedom.
For the degenerated shape elements with the B-bar (KEYOPT(6) = 0), enhanced strain (KEYOPT(6) = 2), or simplified enhanced strain (KEYOPT(6) = 3) formulations specified in coupled-field analyses with structural degrees of freedom, a conventional full (prisms and pyramids) or reduced (tetrahedrons) integration scheme is used.
The film coefficient (if any) is evaluated at average film temperature (TS + TB)/2 for the coupled-thermal analyses (KEYOPT(1) = 11, 110, 111, 1011, 100010, 100110, 100011, and 100111).