ansys.mapdl.core.Mapdl.rstmac#

Mapdl.rstmac(file1='', lstep1='', sbstep1='', file2='', lstep2='', sbstep2='', maclim='', cname='', keyprint='', **kwargs)#

Calculates modal assurance criterion (MAC/FRF) and matches nodal solutions from two results files or from one results file and one universal format file.

Mechanical APDL Command: RSTMAC

Parameters:

file1str

File name ( 248 characters maximum) corresponding to the first results file ( .rst or .rstp file). If the file name does not contain the extension, it defaults to rst.

lstep1str

Load step number of the results to be read in File1.

N - Reads load step N. Defaults to 1.

sbstep1str

Substep number of the results to be read in File1.

N - Reads substep N. Only valid for MAC.
All - Reads all substeps. This value is the default.

file2str

File name ( 248 characters maximum) corresponding to the second file ( .rst, .rstp, or .unv file). If the file name does not contain the extension, it defaults to rst.

lstep2str

Load step number of the results to be read in File2.

N - Reads load step N. Defaults to 1.

sbstep2str

Substep number of the results to be read in File2.

N - Reads substep N. Only valid for MAC.
All - Reads all substeps. This value is the default.

maclimstr

Smallest acceptable criterion value. Must be $e q u a t i o n n o t a v a i l a b l e$ 0 and $e q u a t i o n n o t a v a i l a b l e$ 1. The default value is 0.90.

cnamestr

Name of the component from the first file ( File1 ). The component must be based on nodes. If unspecified, all nodes are matched and used for MAC calculations. If a component name is specified, only nodes included in the specified component are used. Not applicable to node mapping ( Option = NODMAP on macopt ).

keyprintint or str

Printout options:

0 - Printout matched solutions table. This value is the default.
1 - Printout matched solutions table and full MAC table.
2 - Printout matched solutions table, full MAC table and matched nodes table.

Notes

The rstmac command allows the comparison of the solutions from either:

Two different results files. Valid only for MAC calculations.
One result file ( .rst ) and one universal format file ( .unv ).

Either the modal assurance criterion (MAC) or the frequency response function (FRF) correlation method is used. (For more details see POST1 - Modal Assurance Criterion (MAC) POST1 - Frequency response function correlation

The meshes read from File1 and File2 may be different. The nodes of File1 are matched with the nodes of File2 based on either node location (default) or node number. The solutions are compared for the identified pair of matched nodes. The nodes can also be mapped and the solutions interpolated from File1. See the macopt command for all options.

Units and coordinate systems must be the same for both models.

Results may be real or complex; however, if results in File1 have a different type than results in File2, only the real parts of the solutions are taken into account in MAC calculations. The analysis type can be arbitrary for MAC while only harmonic analysis is supported for FRF criteria calculations.

Non-structural degrees of freedom can be considered. Degrees of freedom can vary between File1 and File2, but at least one common degree of freedom must exist.

The solutions read on the results files are not all written to the database; therefore, subsequent plotting or printing of solutions is not possible. A Set displays command must be issued after the rstmac command to post-process each solution.

The corresponding database file ( .db ) for File1 on rstmac must be resumed before running the command in the following cases:

A component ( Cname ) is used on rstmac.
The nodes are mapped ( macopt,NODMAP,YES).
The nodes are matched using a relative tolerance ( macopt,RELTOLN).

rstmac comparison on cyclic symmetry analysis works only if the number of sectors on File1 and File2 are the same, and the database is saved after the solution is finished. Also, a comparison cannot be made between cyclic symmetry results and the full 360 degree model results ( File1 - cyclic solution, File2 - full 360 degree model solution). Comparing cyclic symmetry solutions written on a selected set of nodes ( outres ) is not supported.

The modal assurance criterion values can be retrieved as parameters using the get command ( Entity = rstmac ).

FRF correlation is only supported for the comparison of an .rst and a .unv file. All substeps are considered for both files to define the frequency domain for criteria calculations. The printout options consist of listing the table of the criterion results for each frequency in the frequency domain ( KeyPrint = 0, 1, or 2) and the matched nodes table ( KeyPrint = 2).

Example Usage

For a detailed discussion on using RSTMAC with examples see Comparing Nodal Solutions From Two Models (RSTMAC) RSTMAC ) in the Basic Analysis Guide.