SPMWRITE, Method, NMODE, Inputs, InputLabels, Outputs, OutputLabels, NIC, VelAccKey, FileFormat
Calculates the state-space matrices and writes them to
the SPM file.
MethodReduction method for the calculation of the state-space matrices.
| — | Method based on modal analysis results from LANB, LANPCG, SNODE, or SUBSP eigensolver (default). |
NMODENumber of modes to be used. Defaults to all modes.
InputsDefinition of the inputs. Defaults to all load vectors on the MODE file.
If an integer is entered, it specifies
the number of load vectors from the MODE file used for the definition
of the inputs. The first Inputs load vectors
are used.
If Inputs is an array parameter,
the first column is the node number and the second column is the structural
degree of freedom (1=UX, 2=UY, 3=UZ, 4=ROTX, 5=ROTY, 6=ROTZ) indicating
input points. The number of rows in the array parameter is equal to
the number of inputs.
InputLabelsDefinition of the input labels. Defaults to the load
vector numbers or input definition (node and degree of freedom array
parameter), depending on the Inputs specification.
If a character array parameter is entered (Type=CHAR in the *DIM command), each 8 character string represents an input
label. Only valid when Inputs is an array
parameter
OutputsDefinition of the outputs. Defaults to the inputs.
If an array parameter is entered, the first column is the node number and the second column is the structural degree of freedom (1=UX, 2=UY, 3=UZ, 4=ROTX, 5=ROTY, 6=ROTZ) of the output points. The number of rows in the array parameter is equal to the number of outputs.
OutputLabelsDefinition of the output labels. Defaults to the output
definition (node and degree of freedom) if used, else defaults to
the InputLabels.
If a character array parameter is entered (Type=CHAR in the *DIM command), each 8 character string represents an output label.
NICLoad vector on the MODE file used for the calculation of the initial conditions. Defaults
to no initial condition.
VelAccKey Output velocities and accelerations key.
| — | Output displacements only (default). |
| — | Output displacements, velocities and accelerations. |
FileFormatThe format of the SPM file.
| — | Dense format. |
| — | Matrix Market Exchange format (non-zero terms only). |
| — | Simplorer SML format without reference (default). |
| — | Simplorer SML format with common reference. |
| — | Simplorer SML format with independent references. |
The SPMWRITE generates the file Jobname.SPM containing the state-space matrices and other information.
The following applies to the SML formats (FileFormat = 2, 3, and 4):
For conservative systems where the outputs are equal
to the inputs (Outputs is left blank):
The labels for the inputs (InputLabels) are required.
The Inputs must use the
array parameter option so that the input degrees of freedom (DOFs)
are known.
For non-conservative systems where the outputs are not equal to the inputs:
The labels for the outputs (OutputLabels) are required.
The file formats with references (FileFormat = 3 and 4) do not apply.
Velocity and acceleration results are not included in the state-space matrices calculation (VelAccKey = OFF)
File format with common reference (FileFormat = 3) does not apply if the inputs are based on DOFs of a different nature. All input DOFs must be either all rotational or all translational and not a mix of the two.
A graphics file (Jobname_SPM.PNG) is generated. It contains an element plot of the model.
For more details about the reduction method and the generation of the state-space matrices, see Reduced-Order Modeling for State-Space Matrices Export in the Mechanical APDL Theory Reference.
For examples of the command usage, see State-Space Matrices Export.