CDSMETH
Bulk Data Entry Can be used in the component dynamic synthesis method for generating component dynamic matrices at each loading frequency.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
CDSMETH | CDSID | GTYPE | TF | OSET | TOL | SSF | RSF | ||
CMSOUT | SPID | SPID_F | GP_RC |
Example
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
CDSMETH | 10 | SVDNP | YES | ||||||
CMSOUT | 9000001 | 9000001 | YES |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
CDSID | Identification number of CDSMETH. Default = NONE (Integer) |
|
GTYPE | ||
TF | Generate transfer functions at the connection and interior points
at each loading frequency.
|
|
OSET | Grid set for interior grids. The responses corresponding to
interior grids may be recovered in the residual run. If OSET is specified, TF is automatically set to YES. Default = BLANK (Integer) |
|
TOL | Tolerance value for the Singular Value Decomposition (SVD)
operation that involves pseudo-inversion of the transfer function
matrix to obtain the dynamic stiffness
matrix. <REAL/BLANK> Default = 1.0e-20 |
|
SSF | Structural scale factor used to scale transfer function terms
associated with the structural degrees-of-freedom prior to the
Singular Value Decomposition (SVD)
operation. <REAL/BLANK> Default = 1.0 |
|
RSF | Rotational scale factor used to scale transfer function terms
associated with the rotational degrees-of-freedom prior to the
Singular Value Decomposition (SVD)
operation. <REAL/BLANK> Default = 1.0e-3 |
|
CMSOUT | This is an optional keyword to specify the creation of the
Component Model Synthesis (CMS) superelement generated using the
General Modal method with free - free boundary (Craig-Chang
method). <CMSOUT/BLANK> Default = BLANK |
|
SPID | The starting SPOINT ID to be used in CMS
matrix output for the structural eigenmodes. There is no default.
This is only valid, if CMSOUT is
specified. <INTEGER> |
|
SPID_F | The starting SPOINT ID to be used in CMS
matrix output for the fluid eigenmodes. There is no default, if
fluid grids are present in the model. However, this must be used, if
there are fluid grids in the model. This is only valid, if
CMSOUT is
specified. <INTEGER> |
|
GP_RC | Grid participation recovery control.
|
Comments
- CDSMETH is only supported for Modal Frequency Response Analysis subcase. The responses available for recovery, and the attachment points available for connection in the residual structure, must be specified on a BNDFRE1, BNDFREE, CSET or CSET1 data entry for a modal frequency response analysis in which CDSMETH has been specified.
- Frequencies available for recovery must be specified, using the FREQ or FREQ1 (# ranges from 1 to 5) data entries, in the modal frequency response analysis in which CDSMETH has been specified.
- A MODEL card may be used for additional response output for the optional CMS superelement output.
- Reasonable speedup may be achieved by reducing the number of CSET points in the residual run when CDSMETH is used.
- Performance may be an issue with the Block Matrix Elimination (BME) method for large models. The BME option is only recommended for small models or when other methods fail to work.
- SDAMPING cannot be included in the generation of CMS superelements (CMSMETH entry). SDAMPING can be included in the generation of CDS superelements. If you used SDAMPING in the generation of the combined CDS and CMS (METHOD=GM) superelements, the SDAMPING will be included only in the CDS superelements. Use DMIGMOD to apply SDAMPING in the residual run to the CMS (METHOD=GM) superelements. If SDAMPING is not required for CMS superelements in the residual run, then the corresponding DMIGMOD data can be excluded from the model.