Load Steps
Load step entities define and store load cases for a given analysis.
Load steps are defined by selecting associated load collectors and output blocks.
Abaqus Cards
A load step corresponds to a *STEP definition in Abaqus model
history. Load collectors, output blocks and groups within a load step are exported under the
corresponding *STEP block in the Abaqus input deck.
| Card | Description |
|---|---|
| *ADAPTIVE MESH | Defines an adaptive mesh domain and specifies the frequency and intensity of
adaptive meshing for that domain. Note: Defined in the load step card image.
|
| *BUCKLE | Obtain eigenvalue buckling estimates. Note: Defined in the load step card image.
|
| *BULK VISCOSITY (Explicit) |
Modify bulk viscosity parameters. Note: History data.
|
| *COUPLED TEMP-DISPLACEMENT | Analyze problems where the simultaneous solution of the temperature and
stress/displacement fields are necessary. Note: Defined in the load step card image.
|
| *DYNAMIC (Explicit) |
Dynamic stress/displacement analysis. Note: Defined in the load step card image.
|
| *DYNAMIC (Standard) |
Dynamic stress/displacement analysis. Note: Defined in the load step card image.
|
| *FILE FORMAT | Specify format for results file output and invoke zero-increment results file
output. Note: Defined in the load step card image.
|
| *FREQUENCY | Extract natural frequencies and modal vectors. Note: Defined in the load step
card image.
|
| *GEOSTATIC | Verify that the geostatic stress field is in equilibrium with the applied loads and boundary conditions on the model and to iterate, if needed, to obtain equilibrium. |
| *HEAT TRANSFER | Transient or steady-state uncoupled heat transfer analysis. Note: Defined in
the load step card image.
|
| *LOAD CASE | Begin a load case definition for multiple load case analysis. Note: Defined in
the load step card image.
|
| *MODAL DYNAMIC | Dynamic time history analysis using modal superposition Note: Defined in the
load step card image.
|
| *MONITOR | Define a degree of freedom to monitor. Note: Defined in the load step card image.
|
| Request or suppress output to the message file in an Abaqus/Standard analysis or to the status file in an Abaqus/Explicit analysis. Note: Defined in the load step
card image.
|
|
| *RADIATION_ VIEWFACTOR | Control the calculation of viewfactors during a cavity radiation
analysis. Note: Defined in the load step card image;
visible in *Heat Transfer analysis procedure.
|
| *RESPONSE SPECTRUM | Calculates estimates of peak values of nodal and element
responses. Note: Defined in the load step card image.
|
| *RESTART WRITE | Save and reuse data and analysis results. Note: Defined in the load step
card image.
|
| *STATIC | Static stress/displacement analysis. Note: Defined in the load step card image.
|
| *STEADY STATE DYNAMICS | Steady-state dynamic response based on harmonic excitation. Note: Defined in
the load step card image.
|
| *STEP | Begin a step. Note: Parameters are defined in the load step card image.
|
| *VISCO | Transient, static, stress/displacement analysis with time-dependent material
response (creep, swelling, and viscoelasticity) Note: Defined in the load step
card image.
|
ANSYS Cards
| Card | Description |
|---|---|
| ACEL | Specifies the linear acceleration of the structure. |
| ANTYPE | Specifies the analysis type and restart status. |
| CECMOD | |
| CMACEL | Specifies the translational acceleration of an element component. |
| CMDOMEGA | Specifies the rotational acceleration of an element component about a user-defined rotational axis. |
| CMOMEGA | Specifies the rotational velocity of an element component about a user-defined rotational axis. |
| EQSLV | Specifies the type of equation solver. |
| LSSOLVE | Reads and solves multiple load steps. |
| NLGEOM | Includes large-deflection effects in a static or full transient analysis. |
| NSUBST | Specifies the number of substeps to be taken this load step. |
| OMEGA | Specifies the rotational velocity of the structure. |
| OUTRES | Controls the solution data written to the database. |
| TIME | Sets the time for a load step. |
Nastran Cards
Load step entities directly correspond to Nastran subcase definitions.
Load steps can reference constraint (SPC), static load (LOAD), multi-point constraint
(MPC), fictitious support (SUPORT1), non-linear parameters (NLPARM), eigenvalue extraction
data (METHOD), frequency range (FREQ), damping (SDAMPING), dynamic load (DLOAD), thermal
loading (TEMP), and so on subcase definitions. Other input data is automatically generated
(the SUBCASE header) or may be added to the subcase definition.
| Card | Description |
|---|---|
| NLSTEP | Describes the control parameters for mechanical, thermal and coupled analysis in SOL 400 and for linear contact analysis in SOL 101. |
| SUBCASE | Delimits and identifies a subcase. |
| SUBCOM | Defines a combination subcase. Note: Automatically created when a new load
step of type “Combination Subcase Delimiter” is created. The SUBCOM ID matches
the ID of the HyperMesh load step entity.
|
| SUBSEQ | Subcase sequence coefficients. Note: Only available for Combination Subcase
Delimiter load steps.
Enable SUBSEQ to input combination coefficients. |
| TSTEPNL | Defines parametric controls and data for nonlinear transient structural or heat transfer analysis. |
OptiStruct Cards
Loadsteps directly correspond to OptiStruct subcases. Load steps can reference static loads (LOAD), constraints (SPC), and dynamic loads (DLOAD).
Supported card parameters are dependent upon the selected analysis type (solution sequence).
| Card | Description |
|---|---|
| ACCELERATION | Requests acceleration vector output for all subcases
or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select ACCELERATION. |
| ANALYSIS | Used in the I/O Options section to request that only
a finite element analysis be performed (optimization input is ignored). It may also
be used in the I/O Options or Subcase Information sections to identify the solution
sequence for all subcases or for individual subcases, respectively. Note: Subcase Information Entry
Enable the subcase option ANALYSIS and then select an analysis type. |
| CMSMETH | Requests that only a component mode synthesis solution
be performed and to select a component mode synthesis method definition to be
used. Note: Subcase Information Entry
|
| CSTRAIN | Requests ply strain output for elements referencing
PCOMP, PCOMPP or PCOMPG
properties for all subcases or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select CSTRAIN. |
| CSTRESS | Requests ply stress output for elements referencing
PCOMP, PCOMPP or PCOMPG
properties for all subcases or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select CSTRESS. |
| DESOBJ | Selects a single response definition as the objective
function of an optimization, or to select system response definitions when the
objective function is the least squares sum of these definitions. The
DESOBJ command also indicates if this response is to be
minimized or maximized. Note: Subcase Information Entry
Part of the optimization problem setup, created when you define an objective. |
| DESSUB | Used within a subcase definition, to select a
constraint set that is subcase dependent. Note: Subcase Information Entry
Part of the optimization problem setup, created when you define a dconstraint. |
| DISPLACEMENT | Requests displacement vector output for all subcases
or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select DISPLACEMENT. |
| DLOAD | Selects a dynamic load to be applied in a transient and
frequency response analysis subcase. The DLOAD command can also
be used to select a user-defined loading curve to be applied in a nonlinear static
analysis subcase. Note: Subcase Information Entry
Enable the subcase definition DLOAD and select load collectors with dynamic loading information (DLOAD, RLOAD1, RLOAD2, TLOAD1, TLOAD2). |
| EIGVRETRIEVE | Retrieves eigenvalue and eigenvector results of a
Normal Modes Analysis from an external data file
(.eigv). Note: Subcase Information Entry
|
| EIGVSAVE | Outputs eigenvalue and eigenvector results of a
Normal Modes Analysis to an external data file
(.eigv). Note: Subcase Information Entry
|
| ELFORCE | Requests structural element force output and elemental
fluid particle velocity output for all subcases or individual subcases,
respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select ELFORCE. |
| ERP | Requests equivalent radiated power output for all subcases or
individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select ERP. |
| ESE | Requests strain energy and strain energy density output for
all subcases or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select ESE. |
| EXCLUDE | Selects a set of elements to be excluded from a Linear
Buckling Analysis. Note: Subcase Information Entry
Enable the subcase option OUTPUT to select EXCLUDE, then select a SET definition. |
| FATDEF | Selects a FATDEF Bulk Data Entry
that will define the elements, and their associated fatigue properties, to be
considered for Fatigue Analysis. Note: Subcase Information Entry
|
| FATPARM | Selects a FATPARM Bulk Data Entry
that will define the parameters to be used for a Fatigue Analysis. Note: Subcase Information Entry
|
| FATSEQ | Indicates that a subcase is a fatigue analysis subcase
and to select a FATSEQ Bulk Data Entry that will define the
loading sequence for the Fatigue Analysis. Note: Subcase Information Entry
|
| FREQUENCY | Selects the set of forcing frequencies to be solved
in a frequency response problem. Note: Subcase Information Entry
Enables you to select load collectors with frequency information (FREQ, FREQ1, FREQ2, FREQ3, FREQ4, FREQ5). |
| GLOBSUB | Selects a subcase that references the global structure
for Local-Global Analysis and a set of grid points in the local structure that
defines the cut surface for displacement. Note: Subcase Information Entry
|
| GPFORCE | Requests grid point force balance output for all subcases
or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select GPFORCE. |
| GPSTRESS | Requests grid point stresses output for all subcases or
individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select GPSTRESS. |
| IC | Selects initial conditions for Transient and Explicit
Analysis. Note: Subcase Information Entry
|
| INVEL | Selects a multibody initial velocity set to be applied
in a multibody problem. Note: Subcase Information Entry
|
| LABEL | Provides a subcase with a label. Note: Subcase Information Entry
|
| LOAD | Selects a static load set to be applied in linear static
solutions. Note: Subcase Information Entry
Enables you to select load collectors with static load information (FORCE, MOMENT, PLOAD, PLOAD2, PLOAD4, LOAD), or inertial loading information (GRAV, RFORCE). |
| MBSIM | Selects a Multibody simulation definition to be applied
in a Multibody problem. Note: Subcase Information Entry
|
| METHOD | Selects a method for real eigenvalue
extraction. Note: Subcase Information Entry
Select load collectors with an EIGRL card image for METHOD(STRUCT) or METHOD(FLUID). |
| MLOAD | Selects a Multibody load set to be applied in a
Multibody problem. Note: Subcase Information Entry
Enables you to select load collectors with multi-body dynamic load information (GRAV, MBFRC, MBFRCC, MBMNT, MBMNTC, MLOAD). |
| MODEWEIGHT | Defines a multiplier for computed eigenvalues that
are to be used in the calculation of the "weighted reciprocal eigenvalue" and
"combined compliance index" optimization responses. Note: Subcase Information Entry
Part of the optimization problem setup, created when you define a response. |
| MOTION | Selects a Multibody motion set to be applied in a
multibody problem. Note: Subcase Information Entry
Enables you to select load collectors with multi-body dynamic motion information (MOTION, MOTNG, MOTNGC). |
| MPC | Selects a multi-point constraint set. Note: Subcase Information Entry
|
| MPCFORCE | Requests multi-point force of constraint vector is
output for all subcases or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
|
| NLPARM | Activates nonlinear solution methods for this subcase
and to select the parameters used for Nonlinear Quasi-static Analysis, Geometric
Nonlinear Implicit Analysis, and Nonlinear Direct Transient Analysis. Note: Subcase Information Entry
|
| NSM | Selects a non-structural mass set for mass generation. The
selector command must appear before the first SUBCASE
statement. Note: Subcase Information Entry
|
| OFREQUENCY | Requests a set of frequencies for output requests for
all subcases or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select OFREQUENCY. |
| OLOAD | Requests the form of applied load vector output and
temperature load output for all subcases or individual subcases,
respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select OLOAD. |
| OMODES | Requests a set of modes for output requests for all
subcases or for individual subcases, respectively. This command is applicable for
normal modes and linear buckling solution sequences only. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select OMODES. |
| RESVEC | Controls the calculation of residual vectors. Note: Subcase Information Entry
|
| RSPEC | References combination rules, excitation
degrees-of-freedom, and input spectra for use in response spectrum
analysis. Note: Subcase Information Entry
|
| RWALL | Selects rigid walls for geometric nonlinear
analysis. Note: Subcase Information Entry
|
| SDAMPING | Applies modal damping as a function of natural
frequency in modal solutions. Note: Subcase Information Entry
|
| SOLVTYP | Defines the solver type to be used for static, dynamic
analysis and geometric nonlinear implicit analysis. Note: Bulk Data Entry
|
| SPC | Selects a single-point constraint set. Note: Subcase Information Entry
|
| SPCFORCES | Requests single-point force of constraint vector output
for all subcases or individual subcases, respectively. Note: I/O Options and Subcase Information Entry
|
| STATSUB | Selects a static solution subcase. Note: Subcase Information Entry
|
| STRAIN | Requests strain output for all subcases or individual
subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select STRAIN. |
| STRESS | Requests stress output for all subcases or individual
subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select STRESS. |
| SUBCASE | Indicates the start of a new subcase
definition. Note: Subcase Information Entry
|
| SUBCOM | Delimits and identifies a combination
subcase. Note: Subcase Information Entry
|
| SUBMODEL | Selects a submodel as a set of elements. Subcase
entries specific to the selected element set can be used to solve the submodel
without affecting the rest of the structure. Note: Subcase Information Entry
|
| SUBSEQ | Gives the coefficients for forming a linear combination
of the previous static subcases. Note: Subcase Information Entry
|
| SUBTITLE | Defines the subtitle for all subcases or for individual subcases, respectively. |
| SUPORT1 | Selects a fictitious support set to be applied to the
model. Note: Subcase Information Entry
|
| TEMP | Defines temperature at grid points or a SET of grid points for determination of Thermal Loading and Stress recovery. |
| TSTEP | Selects integration for transient analysis. Note: Subcase Information Entry
|
| TTERM | Used in a geometric nonlinear subcase to define the
termination time. Note: I/O Options and Subcase Information Entry
|
| VELOCITY | Requests velocity vector output for all subcases or
individual subcases, respectively. Note: I/O Options and Subcase Information Entry
Enable the subcase option OUTPUT to select VELOCITY. |
| WEIGHT | Defines a weighting factor (multiplier) for the
compliances of individual linear static solution subcases, which are used in the
calculation of the "weighted compliance" and "combined compliance index"
optimization responses. Note: Subcase Information Entry
|
| XHIST | Selects time history output for geometric nonlinear
analysis. Note: Subcase Information Entry
|
Permas Cards
| Card | Description |
|---|---|
| $CONSTRAINTS | Constraint variant bracket header line. Note: Set AnalysisProcedure to
CONSTRAINTS.
|
| $FREQLOAD | Definition of frequency dependent dynamic loads for use in frequency response
analysis. Note: Only available when AnalysisProcedure is set to
LOADING.
|
| $LOADING | Loading variant bracket header line. Note: Set AnalysisProcedure to
LOADING.
|
| $NLLOAD | Define a nonlinear static load history. Note: Only available when
AnalysisProcedure is set to LOADING.
|
| $SITUATION | Situation definition header line. Note: Set AnalysisProcedure to
SITUATION.
|
| $TRANSLOAD | Definition of time dependent dynamic loads for use in transient response
analysis. Note: TRANSLOAD cards and FREQLOAD cards are mutually
exclusive.
|